901131 Examples

www.aabu.edu.jo/~wael

C++ ProgramA sequence of structured statements written by programmer using C++ language to solve a problem.

Using Visual C++ to write your program

1- Start Programs Microsoft Visual Studio 6 Microsoft Visual C++ 62- File New Files C++ Source file oK3- Write your program using C++ statements4- Compilation: Ctrl + F7 to see if the program has error's5- Execution: to display the program’s result

General form of C++ Program#include <iostream.h>void main() {

.

.C++ statements ..

}

Remark: C++ language is case sensitive

Problem : Compute and print the summation of two numbers.

Program#include <iostream.h>void main() {

int a, b, s;cout<<"Please Enter two numbers:";cin>>a>>b;s = a + b;cout<<"s="<<s<<endl;

}

Remarks:- iostream.h: C++ library that contains all input/output statements and other constrols.- main(): the main function of the program which represents the program’s life time.- a, b, and s are three variables of type integer. Their values can be any integer and can be changed.- cin>>: C++ statement to take value(s) from the user.- cout<<: C++ statements to display value(s) to the output screen.- “ ”: must be around any character constants.- \n or endl: to start new line at output screen.

Variables• Variables:

- Variable is one memory location. -The name of the location is the variable name. -The location content is the value of the variable - You can change the content of the variable at any time in the statements of the algorithm.e.g. Name of the location Inside Memory location employee_name “Ali Ahmed” age 35 hourly_rate 3.25

Predefined Data Types:• int : values (e.g. 5 , -321 , 12) operations (e.g. + , - , * , / , % , >, <, = =, !=, > =, <= )• float (double) : values (e.g. 3.2 , 1.23E+5 , 0.34E-2) operations (e.g. +, -, *, /, , >, <, = =, !=, > =, <= )• bool : values (true , false) operations (e.g. AND, OR, NOT)• char : values (e.g. ‘A’ , ‘t’ , ‘(‘ , ‘5’ , ‘;’ ) operations (e.g. <, > , ≤, etc.)

Data Types

Variable declarationType Variable_name

Constant Values: can be numerical (3, 100, -5, 3.14) or string (‘A’, ‘$’, ‘Ahmad’, Amman).

Constant identifier: one memory location take a value at a first time, which can not be changed.

const float pi = 3.14

Variable names

• int X,x,Number, IF,If,iF,a7,Total_sum;• float _abc;

Problem : Compute and print the average of three numbers.

Program

#include <iostream.h>void main() {

int n1, n2, n3;float s, average;cout<<"Please Enter three integers: ";cin>>n1>>n2>>n3;s = n1 + n2 + n3;average = s / 3;cout<<"\n Average = \t"<<average<<endl;

}

Remark: \t to leave tab spaces

Problem : Compute the area of the circle. Where area = π x R2


const double Pi = 3.14;int r;cout<<"\n Please enter r";cin>>r;double a;a = Pi * r * r;cout<<"\n Circle's Area = "<<a<<endl;

}

Examples on integer division#include <iostream.h>void main( ){int x;x=1/3*3; // 1/3=0cout<<x<<endl;x=1.0/3*3; cout<<x<<endl;}

Boolean variables and relational operations

#include <iostream.h>void main( ){bool x,y;x= 5 > 7;cout<<x<<endl;y= 5 < 7;cout<<y<<endl;x=true;cout<<x<<endl;y=false;cout<<y<<endl;x=5;cout<<x;}

Misleading examplesX= 7 > 5 > 3;This expression gives false because its evaluated

as followsX=(7>5) >3; = 1 > 3; // False;The relational operations are executed from left to

right < ,<= ,> , >= have the same priority== , != have lower priority than the above.X = 1 == 1>3;X = 3>4 == 4>3;

Priority

• * , / , % have the same priority ( High )• + , - have the same priority (Low)

Examples on arithmetic operationsX= 5 + 2 * 3 – 7;The order of execution is as follows: * , then + , then -

X= 5 + 2 * 3 – 7 / 3 Execution order : * , + , / , -

X= 5+2*3/4%1-7/3……………………..

If Statement in C++

One way ifif ( Condition )

statement;

if ( Condition ) {statements; }

Problem : Read any number from the user, then print positive if it is positive.

Program


int Num;cout<<"\n Please Enter an integer number:";cin>>Num;if (Num > 0)

cout<<" Positive\n";}

Another Version

#include <iostream.h>void main() {int Num;bool w;cout<<"\n Please Enter an integer number:";cin>>Num;w=Num>0;if (w)cout<<" Positive\n";}

If Statement in C++Two way if

if ( Condition )statement;

elsestatement;

if ( Condition ) {statements; }

else {statements;}

Write a program that reads a mark, if mark is 60 or greater, the program prints PASS, else it will print FAIL#include <iostream.h>

void main() {int mark;cout<<"\n Please Enter your mark: ";cin>>mark;if (mark>=60)cout<<" PASS\n";else cout<<"FAIL\n";

}

More than one statement in the if#include <iostream.h>

void main() {int mark;cout<<"\n Please Enter your mark: ";cin>>mark;if (mark>=60){cout<<" PASS\n";cout<<“ you can take Object course now\n”;}else {cout<<"FAIL";cout<<“You must take this course again\n”;}

}

Write a program that prints the fraction a/b in the form c d/bExample: 7/3 = 2 1/3

#include <iostream.h>void main ( ) {int a,b,c,d;cout<<“To convert the fraction from the format a/b

to c d/b, Enter a,b”;cin>>a>>b;c=a/b;d=a%b;cout<<a<<“/”<<b<<“=“<<c<<“ “<<d<<“/”<<b<<endl;}

Enhancement on the previous example#include <iostream.h>void main ( ) {int a,b,c,d;cout<<“To convert the fraction from the format a/b to c d/b,

Enter a,b”;cin>>a>>b;c=a/b;d=a%b;cout<<a<<“/”<<b<<“=“;if ( c != 0) cout<<c;if (d!=0) cout<<“ “<<d<<“/”<<b;cout<<endl;}

ConditionCondition: An expression that is evaluated to produce only true or false values.

Arithmetic Expressions - It is composed of operands and arithmetic operations ( + , - , *, /, %). - Its result is a numeric value (e.g. 3 + 4 gives 7) - Operands may be numbers and/or identifiers that have

numeric values.

Relational Expressions - It is composed from operands and operators. - Operands may be numbers and/or identifiers that have numeric values - Its result is a logical value (true or false). - Operators are relational operators: < , > , <= , >= , = =, != e.g. (a < b) gives true, if value of a is less than value of b false, if value of a is not less than value of b

(x != y) also gives true or false according to the values of x and y

Logical Expressions - It is called also Boolean expression. - It is composed from operands and operators. - Operands are identifiers that have logical values - Its result is a logical value (true or false) (see later). - Operators are logical: &&(AND) , ||(OR), !(NOT)

e.g. X && Y a && b || c

Evaluating Logical Expressions

• The truth table(1) AND table

&& True False True True False False False False

(2) OR table || True False True True True False True False

(3) NOT table ! True False False True

Arithmetic Relational Logical

• NOTES1) A relational expression may contain arithmetic sub

expressions, e.g. ( 3 + 7 ) < (12 * 4 )

3 + 7 < 12 * 42) A logical expression may contain relational and

arithmetic subexpressions, e.g.1- x && y && ( a > b )2- (2 + t ) < (6 * w ) && ( p = =q )

Operator PrecedenceOperator Description Precedence

( ) parentheses Highest +, – , ! unary plus, unary minus,

Not *, /, % + , - Binary plus, binary minus

<, <=, >, >= == , != Equal, not equal && || = Assignment Lowest

Examples• Find the value of the following expression:(1) 5 + 8 * 2 / 4 16

4

9 (This is the final result)

Find the value of the following expression

( 9 + 3 ) - 6 / 3 + 5

12 2 10`

15 (this is the final result)

Find the value of the following Expression

If x = True, y = False, z = False, find the value of the expression x && y || z

x && y || z

False

False (the final result)

Another example

• X=true, Y=false, Z= true

X || Y && Z true

• X=true, Y=false, Z= falseX || Y && Z

true

If a = 3, b = 5, x = true, y = false, find the value of the expression: ( a < b ) AND y OR x

( a < b ) && y || x

True

False

True (the final result)

Find the value of the following Expression

What is the output of the following code:

Program

#include <iostream.h>void main() {int a=10, b=3;cout<<"\n a+b= \t"<<a+b;cout<<"\n a+b*2= \t"<<a+b*2;cout<<"\n (a+b)*2 \t"<<(a+b)*2<<endl;cout<<a<<“<“<<b<<" is\t"<<(a<b);cout<<"\n a+b != a+3 is \t"<<(a+b != a+3);cout<<"\n a+b >= b*2 || a>b+9 is \t"<<(a+b >= b*2 || a>b+9); cout<<endl;}

Problem : Read any number from the user, then print positive if it is positive and print negative otherwise.

Program


int Num;cout<<"\nPlease Enter Number:";cin>>Num;if (Num < 0)

cout<<"\nNegative\n";else

cout<<"\nPositive\n";}

Problem : Read Two numbers from the user, then print the greatest one.


int x,y;cout<<"\nPlease Enter two numbers:";cin>>x>>y;cout<<"Max = ";if (x > y)

cout<<x<<endl;else

cout<<y<<endl;}

Problem : Read three numbers to print the smallest one.


int a, b, c;cout<<"\nPlease Enter three numbers:";cin>>a>>b>>c;cout<<"\nMin= ";if ((a < b) && (a < c))

cout<<a;if ((b < a) && (b < c))

cout<<b;if ((c < a) && (c < b))

cout<<c;cout<<endl;

}

Program2 (Nested if)#include <iostream.h>void main() {

int a, b, c;cout<<"\nPlease Enter three numbers:";cin>>a>>b>>c;cout<<"\nMin= ";if (a < b)

if (a < c)cout<<a;

elsecout<<c;

elseif (b < c)

cout<<b;else

cout<<c;cout<<endl;

}

Problem : Read number, if it is positive, Add number 10 to it and print the Number “is positive”, but otherwise, subtract number 10 from it and print the Number “is negative”.


int Number;cout<<"\nPlease enter Number:";cin>>Number;if (Number>0) {

Number = Number + 10;cout<<Number<<" is Positive\n";}

else {Number = Number - 10;cout<<Number<<" is Negative\n";}

}

Example on dangling else

if ( x>y) if ( x<z) cout<<“ Hello”;

else cout<<“Hi”;

Another idea

if ( x>y) {if ( x<z) cout<<“ Hello”;}else cout<<“Hi”;

Assignment StatementSimple Assignment:

Max = 5 ;Max = A ;F = A+B*2;

Compound Assignment:A += 10 ; A = A + 10;A -= C ; A = A – C;I *= 4 ; I = I * 4;r /= 2; r = r / 2;S %= 3 ; S = S % 3 ;B &= true; B = B && true;B |= true; B = B || true;

Increment and DecrementPostfixC++; use the value of C, then increment (C = C+1) it.C--; use the value of C, then decrement (C = C-1) it.

Prefix++C; increment the value of C (C = C+1), then use it .--C; Decrement the value of C (C = C-1), then use it .

What is the output of the following C++ Source Code

Program#include <iostream.h>void main( ) {

int A=10, B=4, R;cout<<"A="<<A<<"\tB="<<B;A += B;B *= 2;cout<<"\nA="<<A<<"\tB="<<B;R = ++A % B--;cout<<"\nR="<<R;R = A++ + --B ;cout<<"\nA="<<A<<"\tB="<<B<<"\tR="<<R;bool a=true, b=false;a &= b;if (a == 0)

cout<<"\n a = false\n";else

cout<<"\n a = true\n";}

Examples

X=5;Y=7;Z=X++ + Y; // Z=X+Y; X=X+1;cout<<X<<“ “<<Y<<“ “<<Z<<endl;Z=++X +Y; // X=X+1; Z=X+Y;cout<<X<<“ “<<Y<<“ “<<Z<<endl;Z=X++ + Y++; // Z=X+Y; X++;Y++;cout<<X<<“ “<<Y<<“ “<<Z<<endl;

Loop (iteration statements)used to repeat subcode number of times

there three loop techniques:1- for Loop.2- while Loop.3- do … while Loop

For Loop TechniqueGeneral Form:for (counter_var=initial_val; condition; increasing or decreasing counter_var)

{.Statement(s); .

}

Statements will be executed repeatedly while condition is true. When the condition become false, the loop will be terminated and the execution sequence will go the first statement after for loop.

If the loop body contains only one statement, there is no need to begin{ and end } the loop body.

Problem : Print the word “Amman” five times. Program#include <iostream.h>void main( ) {

for (int i=1; i<=5; i++) cout<<"Amman\n";

}

Another Program#include <iostream.h>void main() {

for (int i=5; i>=1; i--) cout<<"Amman\n";

}

Problem : Print the following numbers.1 3 5 7 9 11

Program#include <iostream.h>void main( ) {

for (int k=1; k<=11; k+=2) cout<<k<<“\t”;

cout<<endl;}

Problem : Print the following numbers.20 17 14 11 8 5 2

Program


for (int m=20; m>=2; m-=3) cout<<m<<“\t”;

cout<<endl;}

Another Version of the previous example

#include <iostream.h>void main( ) {

int m;for (m=20; m>=2; m-=3)

cout<<m<<“\t”;cout<<endl;

}

Problem : Print the following numbers.1 2 3 4 … n(entered by user)

Program


int n;cout<<"\nPlease enter the upper limit:";cin>>n;for (int i=1; i<=n; i++)

cout<<i<<“\t”;cout<<endl;

}

Problem : Print the following numbers.L (entered By user) (L+1) (L+2) … U (entered By user)


int L,U;cout<<"\nPlease enter the Lower limit:";cin>>L;cout<<"\nPlease enter the Upper limit:";cin>>U;for (int i=L; i<=U; i++)

cout<<i<<“\t”;cout<<endl;

}

Problem : Read five numbers from the user and print the positive numbers only.


int num;for (int i=1; i<=5; i++)

{ cout<<"\nPlease Enter No"<<i<<':'; cin>>num; if (num > 0)

cout<<num; }

}



int num;for (int i=1; i<=5; i++) {

cout<<"\nPlease enter the next number:";cin>>num;if (num<0)

continue;cout<<num; }

}

Problem : Compute and print S, Where S = 1+ 2+ 3+ 4+ 5

Program


int S=0;for (int i=1; i<=5; i++)

S+=i;cout<<"\nS="<<S<<endl;

}

Problem : Compute and print S, Where Sum = 1+ 3+ 5+ 7+ … + n


int Sum=0, n;cout<<"\nPlease Enter n";cin>>n;for (int i=1; i<=n; i+=2)

Sum+=i;cout<<"\nSum="<<Sum<<endl;

}

Problem : Compute and print the summation of any 10 numbers entered by the user.

Program


int S=0, N;for (int i=10; i>=1; i--) {

cout<<"\nPlease Enter the next number:";cin>>N;S+=N;}

cout<<"\nS="<<S<<endl;}

Problem : Compute and Print the factorial of the number 5. (Fact = 5 * 4 * 3 * 2 * 1)

Program


int Fact=1;for (int j=5; j>=1; j--)

Fact *= j;cout<<"5!= "<<Fact<<endl;

}

A program to find n!


int Fact=1,n;cout<<“Enter an integer to find its factorial”;cin>>n;for (int j=n; j>=1; j--)

Fact *= j;cout<<n<<"!= "<<Fact<<endl;

} Try it on n = 17 ???

Problem : Compute and Print the value of M where M = 2 * 4 * 6 * … * n

Program


long M=1;int n;cout<<"please enter the upper Limit:";cin>>n;for (int i=2; i<=n; i+=2)

M *= i;cout<<"M= "<<M<<endl;

}

Problem : Compute and Print Mn


long Result=1;int M, n;cout<<"please enter the Base number:";cin>>M;cout<<"\nplease enter the exponent:";cin>>n;for (int i=1; i<=n; i++)

Result *= M;cout<<"\nResult= "<<Result<<endl;

}

Write a program that finds Mn for positive & negative n

• H.W.

Print the following shape*************************cin>>n;for(int i=1;i<=n;i++) { for (int j=1;j<=n;j++) cout<<“*”; cout<<endl; }

Nested for

Problem : Draw the following shape***************


for (int raw=1; raw<=5; raw++) {for (int C=1; C<=raw; C++)

cout<<'*';cout<<endl; }

}

Nested for



for (int i=1; i<=5; i++) {for (int j=i; j<=5; j++)

cout<<'*';cout<<endl; }

}

What is the output for the following program

for(int i=1;i<=5;i++){ for (int j=1;j<=5;j++) if (i==j) cout<<“*”; else if (i+j==6) cout<<“*“; else cout<<“ “;Cout<<endl;}

Problem : display the multiplication table for the number 3.


for (int i=1; i<=10; i++)cout<<"3 x "<<i<<" = "<<3*i<<endl;

}

Problem : display the multiplication table for the numbers from 1 to 5.

1 2 3 4 52 4 6 8 103 6 9 12 154 8 12 16 205 10 15 20 25

for (int i=1;i<=5;i++) {

for(int j=1;j<=5;j++) cout<<i*j<<“\t”; cout<<endl;

}

Problem : Read any number from the user and print Prime if it is a prime number, or Not prime otherwise.


bool Prime = true;int i, num;cout<<"Please enter the number:";cin>>num;for ( i=2; i<num; i++)

if (num%i==0) {Prime = false;break; }

if (Prime)cout<<num<<" is a Prime number\n";

elsecout<<num<<" is not a Prime number\n";

}

S=m0 + m1 + … +mn

#include <iostream.h>void main(){int s=0,n,m;int t=1;cout<<"Enter m please ";cin>>m;

cout<<"Enter n please ";cin>>n;for (int i=0;i<=n;i++){ t=1; for (int j=1;j<=i;j++) t=t*m;s=s+t;}cout<<s<<endl;

}

#include <iostream.h>void main(){int s=0,n,m;int t=1;cout<<"Enter m please ";cin>>m;

cout<<"Enter n please ";cin>>n;for (int i=0;i<=n;i++){s=s+t;t=t*m;}cout<<s<<endl;

}

While Technique

General Form:while (Condition) {.Statement(s); .

}

Statements will be executed repeatedly while condition is true. When the condition become false, the loop will be terminated and the execution sequence will go to the first statement after While loop.

If the loop body contains only one statement, there is no need to begin{ and end } the loop body.

Problem : Print the word “Amman” five times. Program


int i=1;while (i<=5)

{cout<<"Amman\n";i++;}

}


int i=1;while (i++<=5)

{cout<<"Amman\n";}

cout<<i<<endl;}

Problem : Print the following numbers.1 3 5 7 9 11


int i=1;while (i <= 11) {

cout<<i<<'\t';i+=2; }

}

Remark:Write ((i+=2) <= 11 ) condition instead of the above one. What changes you have to do to produce the same output.

Problem : Print the following numbers.20 17 14 … n


int n, k=20;cout<<"Enter the lower limit:";cin>>n;while ( k >= n) {

cout<<k<<'\t';k -= 3; }

}

Remark:Write k-=3 instead of k in the above condition. What you have to do to produce the same output.


Program


int num, j=0;while ( j++ < 5 ) {

cout<<"Enter the next num:";cin>>num;if (num > 0)

cout<<num<<endl; }}

Remark:Solve the above problem by using continue statement.


int sum=0,i,x,y;cout<<"Enter x,y please: ";cin>>x>>y;i=x;while ( i <=y) {

sum=sum+i;i=i+1;

}cout<<"The Sum for the numbers from "<<x<<" to "<<y<<" = "<<sum<<endl;

}

Problem : Compute and print S, Where Sum = 1+ 3+ 5+ 7+ … + n


int n, Sum=0, i=1;cout<<"Enter the upper limit:";cin>>n;while ( i <= n ) {

Sum += i;i += 2; }

cout<<"\nSum="<<Sum;}

Problem : Read 10 numbers by the user and compute and print the summation of numbers, which are divisible by 3.


int Num, Sum=0, i=1;while ( i <= 10 ) {

cout<<"Enter a number:";cin>>Num;if (Num % 3 == 0)

Sum += Num;i++; }

cout<<"\nSum="<<Sum;}

Problem : Compute and Print the value of M where M = 2 * 4 * 6 * … * n

Program


int N, M=1, i=2;cout<<"Enter the upper limit:";cin>>N;while ( i <= N ) {

M *= i;i += 2; }

cout<<"\nM="<<M;}


int N, M=1, i=2;cout<<"Enter the upper limit:";cin>>N;cout<<"\nM=1";while ( i <= N ) {

M *= i;cout<<"x "<<i;i += 2; }

cout<<"="<<M<<endl;}

Nested Loops#include <iostream.h>void main() {

int i,j=1;while(j<=4){

i=1;while(i<=4){cout<<i<<"\t";i++;

}j++;

cout<<endl;}

}

1 2 3 41 2 3 41 2 3 41 2 3 4



int i=1;while (i<=5) {

int j=1;while (j<=i)

{cout<<'*';j++;}

cout<<endl;i++; }

}

Do .. While Technique

General Form:do {.Statement(s); .

} while (Condition) ;

Statements will be executed repeatedly while condition is true. When the condition become false, the loop will be terminated and the execution sequence will go to the first statement after the loop.

The loop body will be executed at least one.

Problem : Print the word “Amman” five times. Program


int i = 1;do {

cout<<"Amman\n";i++;

} while (i <= 5);}

Execute the following program#include <iostream.h>void main() {

int Choice, Num;do {

cout<<"\n Enter the New Number";cin>>Num;if (Num % 2 == 0)

cout<<Num<<" is Even\n";else

cout<<Num<<" is Odd\n";cout<<"Select your choice.\n";cout<<"1- Exit. (Terminate the Run)\n";cout<<"2- Enter New Number to Check.\n";cin>>Choice;

} while (Choice != 1);}


int Num; char Choice;do {

cout<<"\n Enter the New Number";cin>>Num;if (Num % 2 == 0)

cout<<Num<<" is Even\n";else

cout<<Num<<" is Odd\n";cout<<“Enter Y to continue, any other character to

exit \n”;cin>>Choice;

} while (Choice == ‘Y’);}


int Num; char Choice;do {cout<<"\n Enter the New Number";cin>>Num;if (Num % 2 == 0)cout<<Num<<" is Even\n";elsecout<<Num<<" is Odd\n";cout<<"Enter Y to continue, any other character to exit \n";cin>>Choice;} while ((Choice == 'Y') || (Choice=='y'));

}

Homework

Resolve all problems in the presentation 5 and 6 by using the three loop techniques: For, While, and Do … while Loops.

11 21 2 41 2 4 8

for (int i=1;i<=4;i++){int x=1; for(int j=1;j<=i;j++)

{cout<<x<<“ “; x=x*2;} cout<<endl;}

for (int i=1;i<=4;i++){for(int j=0;j<i;j++)

{int x=1;for( int k=1;k<=j;k++)

x=2*x;cout<<x<<“ “;}

cout<<endl;}

Functions

Chapter 3

Topics to be covered• C++ pre defined functions:

– Math library functions– Random function – Examples on rand with switch statments

• User Functions:– Function proto type– Function definition:

• Square, Cube examples• Examples on the four forms of functions, And their

meaning ( when to use each form):– void F(void)– void F(int)– int F(void)– int F(int)

• Call by value & call By reference• Functions on arrays• Scope of variables &Global variables• Recursion :

– Factorial– Febonacci,– Sum of numbers from x to y

• Math library functions:– ceil(x),floor(x)– fabs(x), fmod(x,y), pow(x,y),sqrt(x)– sin(x), cos(x), tan(x)

• These functions are of type double, and take also double arguments

• They belong to the library – #include <cmath>

Examplescout<<ceil(5.2);ceil(0.1);ceil(-0.1);ceil(-1.1);floor(5.2);floor(0.1);floor(-0.1);floor(-1.1);ceil(5.2/3);floor(ceil(5.2/3));fabs(-17.231);fmod(5,3) ≡ 5%3fmod(4.2,2);fmod(5.1,2.5)fmod(7.7,2.5)

double Y;

Y=pow( 5,4);

Y=pow(5,-4);

Y=pow(5.2,3);

Y=pow(16,0.25);

Y=pow(0.01,0.5);

Y=pow(-4,0.5); runtime error

Y=pow(x*3/7,y-1);

Y=pow(floor(x/3),ceil(x/4));

Y=sqrt(9);

Y=sqrt(10);

Y=sqrt(0.09);

Y=sqrt(-16); runtime error

#include <iostream.h>#include <cmath>

void main(){

double A,B,C,X,Y;cout<<"Enter a number :";cin>>X;Y=X/180*3.141592;A=sin(Y);B=cos(Y);C=tan(Y);cout<<“sin("<<X<<") = "<<A<<endl;cout<<"cos("<<X<<") = "<<B<<endl;cout<<"tan("<<X<<") = "<<C<<endl;

}

Problem : Read any number from the user and print it is prime if it is, or not prime otherwise.

#include <iostream.h>#include <cmath>void main() {

bool Prime = true;int i, num;cout<<"Please enter the number:";cin>>num;for ( i=2; i<=sqrt(num); i++)

if (num%i==0) {Prime = false;break; }

if (Prime)cout<<num<<" is a Prime number\n";

elsecout<<num<<" is not a Prime number\n";

}

Random number generator

• #include <cstdlib>• X=rand(); // gives a random number

// between 0.. 32767

#include <iostream.h>#include <cstdlib>void main(){

int x;for( int i=1;i<=100;i++){x=rand();cout<<x<<endl;}

}

Generate 20 random numbers between 0 - 9


int x;for( int i=1;i<=20;i++){x=rand()%10;cout<<x<<endl;}

}

20 numbers between 1 - 10#include <iostream.h>#include <cstdlib>void main(){

int x;for( int i=1;i<=20;i++){x=rand()%10+1;cout<<x<<endl;}

}

Generate 10 integer random numbers between 5 - 7

Using srand function#include <cstdlib>void main(){

int x,seed;cout<<"Enter the seed for the random generater ";cin>>seed;srand(seed);for( int i=1;i<=10;i++){x=rand();cout<<x<<endl;}

}

Q: Write a program that generates 1200 random numbers between 1-6, and also counts the occurrence of each number?

Its expected that the occurrence of each number will be about 200 times.

But remember we are talking about random number. No exact values.

#include <iostream.h>#include <cstdlib>void main(){ int x,count1=0, count2=0, count3=0, count4=0, count5=0, count6=0;

for( int i=1;i<=1200;i++){x=rand()%6 +1;if (x==1) count1++;if (x==2) count2++;if (x==3) count3++;if (x==4) count4++;if (x==5) count5++;if (x==6) count6++;cout<<x<<endl;}

cout<<1<<" : "<<count1<<endl;cout<<2<<" : "<<count2<<endl;cout<<3<<" : "<<count3<<endl;cout<<4<<" : "<<count4<<endl;cout<<5<<" : "<<count5<<endl; cout<<6<<" : "<<count6<<endl;}

#include <iostream.h>#include <cstdlib>void main(){ int x,count[7]={0};

for( int i=1;i<=1200;i++){x=rand()%6 +1;if (x==1) count[1]++;if (x==2) count[2]++;if (x==3) count[3]++;if (x==4) count[4]++;if (x==5) count[5]++;if (x==6) count[6]++;cout<<x<<endl;}

for(i=1;i<=6;i++) cout<<i<<" : "<<count[i]<<endl;

}

A program to count the occurrence of each random number

The same example using Switch statement

#include <iostream.h>#include <cstdlib>void main(){ int x,count[7]={0};

for( int i=1;i<=1200;i++){x=rand()%6 +1;switch(x) {case 1: count[1]++;

break;case 2: count[2]++; break;case 3: count[3]++; break;case 4: count[4]++; break;case 5: count[5]++;

break;case 6: count[6]++; }}for(i=1;i<=6;i++) cout<<i<<" : "<<count[i]<<endl;

}

• Do the same prev. example, • Count the number of even numbers, and

the number of odd numbers.

#include <iostream.h>#include <cstdlib>void main(){ int x,even=0,odd=0;

for( int i=1;i<=1200;i++){x=rand()%6 +1;switch(x) {case 1:case 3:case 5: odd++;

break;case 2:case 4:case 6: even++;}}cout<<"Even count is "<<even<<endl;cout<<"Odd count is "<<odd<<endl;

}


int x,count[7]={0};for( int i=1;i<=1200;i++){x=rand()%6 +1;count[x]++;

cout<<x<<endl;}

for(i=1;i<=6;i++) cout<<i<<" : "<<count[i]<<endl;

}

User Defined Functions

• Write a function that calculates and returns the square value of a double number:

#include <iostream.h>double square(double); // function prototype

void main( ){double x,y;cout<<“Enter a number :”;cin>>x;y=square(x);cout<<x<<“ squared = “<<y<<endl;}double square(double a){ double b;b=a*a;return b;}

Another user defined function

• Write a program to calculate and print a rectangle area, the program should use a function to calculate and returns the area of a rectangle to the main program?

• This function should take the length and the width , and should return the area

#include <iostream.h>double area(double,double); // function prototype

void main( ){double L,W,A;cout<<“Enter the length:”;cin>>L;cout<<“Enter the width:”;cin>>W;A=area(L,W);cout<<“The area of the recangle is “<<A;}

double area(double X,double Y){ double Z;Z=X*Y;return Z;}

• Write a program that finds and prints the maximum of three integer numbers, The program should use a function to find the maximum value.

#include <iostream.h>int max(int,int,int);

void main(){int x,y,z;cout<<"Enter 3 numbers please :";cin>>x>>y>>z;cout<<"The Maximum is "<<max(x,y,z)<<endl;

}

int max(int a,int b,int c){int m;m=a;if (m<b) m=b;if (m<c) m=c;return m;}

#include <iostream.h>#include <cmath>bool prime(int);

void main(){int x;cout<<"Enter a number please :";cin>>x;if (prime(x))

cout<<x<<" is a prime number\n";else

cout<<x<<" is not a prime number\n";}

bool prime(int a){bool p=true;for(int i=2;i<=sqrt(a);i++) if (a%i==0) { p=false;

break;}

return p;}

Build your own fabs function#include <iostream.h>double fabs(double);void main(void){

double x,y;cout<<"Enter a number ";cin>>x;y=fabs(x);cout<<"The absolute value of "<<x<<" is "<<y<<endl;

}double fabs(double m){

if (m>=0) return m;

elsereturn -m;

}

Forms of functions• Functions that take inputs and returns output:

– double square(double), int max(int a, int b, int c) ….• Functions that take inputs but don’t return output

– void Printsum(int x,int y)• Functions that don’t take any inputs but returns an

output:• int Read_number(void);• Functions that don’t take and inputs and don’t

return any input• void Print_hello(void);

Write a program that uses a function to calculate and print the sum of two numbers.#include <iostream.h>void print_sum(int,int);void main(){int x,y;cout<<“Enter two numbers please :”;cin>>x>>y;print_sum(x,y);}

void print_sum(int x,int y){int s;s=x+y;cout<<x<<“+”<<y<<“ = “<<s<<endl;}

Write a program that reads two numbers and prints the sum of them,

This program should use a function to read the numbers and use another function to

calculate and print the sum of two numbers

#include <iostream.h>void print_sum(int,int);int read_number(void);void main(){int x,y;x=read_number();y=read_number();print_sum(x,y);}

void print_sum(int x,int y){int s;s=x+y;cout<<x<<“+”<<y<<“ = “<<s<<endl;}

int read_number(void){int A;cout<<“Enter a number please “;cin>>A;return A;}

Write a progam that uses a function to print a welcome message

#include <iostream.h>void print_welcome(void);void main(){print_welcome();}

void print_welcome(void){cout<<“Hello, Welcome in C++ functions\n”;}

• Modify the previous example, make the main calls the print function 10 times

• Also, make the print_welcome function print a random message from 3 different messages

#include <iostream.h>#include<cstdlib>void print_welcome(void);void main(){for(int i=1;i<=10;i++)

print_welcome();}

void print_welcome(void){int x=rand()%3;switch(x)

{case 0: cout<<“Hello \n”; break;case 1: cout<<“Welcome \n”;break;case 2: cout<<“Hi, how are u \n”;}

}

Inputs for any function

• The inputs for a function could be:– constants: x=sqrt( 9);– Variables x=sqrt(y);– Expression x=sqrt(y+3*z);– Or even another function x=sqrt(ceil(y/3));

• This is valid for library functions , and user defined functions also

Scope of variables with functions#include <iostream.h>int x=10; // global variablesint f1(int);void f2(int);int f3(void); // int f3();

void main(void){cout<<x<<endl;int x=15;cout<<x<<endl;cout<<::x<<endl;for (int i=1;i<3;i++){ int x=5; int y=x+::x; cout<<y<<" "<<x<<" "<<::x<<endl;}cout<<x<<endl;cout<<f1(x)<<endl;cout<<::x<<endl;}

int f1(int a){

cout<<x<<endl;int x=13;cout<<x<<endl;f2(x);cout<<::x<<endl;return x+a;

}

void f2(int b){cout<<x<<endl;x=x-b;cout<<x<<endl;}

Aliasing#include<iostream.h>int main(){

int x;int &y=x;x=5;int &z=y;cout<<x<<"\t"<<y<<"\t"<<z<<endl;y=7;cout<<x<<"\t"<<y<<"\t"<<z<<endl;y=x+z-3;cout<<x<<"\t"<<y<<"\t"<<z<<endl;return 0;

}

Call By value & call By reference#include <iostream.h>int square(int);

void main(){

int x,y;cout<<"Enter a number ";cin>>x;y=square(x);cout<<x<<" squared is "<<y<<endl;

} int square(int a) // call by value { a=a*a; return a; }

#include <iostream.h>void square(int &);

void main(){

int x;cout<<"Enter a number ";cin>>x;cout<<x<<" squared is “;

square(x);cout<<x<<endl;

} void square(int & a) // call by reference { a=a*a; }

#include<iostream.h>void read_two_numbers(int &,int &);

void main(){int x,y;read_two_numbers (x,y);cout<<x<<" "<<y<<endl;}

void read_two_numbers (int & a,int &b){

cout<<“Enter two numbers please “ cin>>a>>b;}

Static variables and default arguments

#include <iostream.h>void f(int x=10 );void main(){f();f(5);f(7);}

void f(int x){static int abc=17;abc++;cout<<abc<<"\t"<<x<<endl;}

Recursive functions

• Factorial• Febonacci series• Sum between X, Y

#include <iostream.h>int fact(int);void main(){

int x;cout<<"Enter a number to calculate its factorial ";cin>>x;cout<<x<<"! = "<<fact(x)<<endl;

}

int fact(int n){

if (n==1) return 1;

else return n*fact(n-1);

}

Recursive fact

Recursive fact#include <iostream.h>int fact(int);void main(){


}

int fact(int n){

if (n==1) {cout<<"Now returning fact 1\n";

return 1;}else{cout<<"Now calling fact "<<n-1<<endl; return n*fact(n-1);}

}

#include <iostream.h>int fact(int);void main(){


}

int fact(int n){

if (n==1) {cout<<"Now returning fact 1\n";

return 1;}else{cout<<"Now calling fact "<<n-1<<endl;int m= n*fact(n-1);cout<<"Returning "<<n<<"!="<<m<<endl;return m;}

}

• Feb(0)=0• Feb(1)=1• Feb(n)=feb(n-1)+feb(n-2)

#include <iostream.h>int feb(int);void main(){

int x;cout<<"Enter a number to calculate its febonacci ";cin>>x;cout<<"Feb("<<x<<") = "<<feb(x)<<endl;

}

int feb(int n){

if (n==0) return 0;elseif (n==1) return 1;elsereturn feb(n-1)+feb(n-2);}

#include <iostream.h>int feb(int);void main(){

int x;cout<<"Enter a number to calculate its febonacci ";cin>>x;cout<<feb(x)<<endl;

}

int feb(int n){if (n==0) return 0;elseif (n==1) return 1;else return feb(n-1)+feb(n-2);}

Febonacci using for#include <iostream.h>int feb(int);void main(){

int x;cout<<"Enter a number to calculate its febonacci ";cin>>x;cout<<feb(x)<<endl;

}

int feb(int n){int fn_2=0;int fn_1=1;int fn;for(int i=2;i<=n;i++) {fn=fn_2+fn_1; fn_2=fn_1; fn_1=fn; }return fn;}

Sum of numbers from 1 to n#include <iostream.h>int sum(int);void main(){

int x;cout<<"Enter a number to calculate the sum ";cin>>x;cout<<“Sum of the series “<<sum(x)<<endl;

}

int sum(int n){

if (n==1) return 1;

else return n+sum(n-1);

}

• Write a function that returns the sum of numbers from X to Y. The function should calculate the sum recursively

• ∑ i = y+ ∑ i i=x

y

i=x

y-1

Sum of numbers from X to Y

#include <iostream.h>int sum(int,int);void main(){

int x,y;cout<<"Enter two numbers to calculate the sum ";cin>>x>>y;cout<<“Sum of the series “<<sum(x,y)<<endl;

}

int sum (int a, int b){

if (a==b) return b;

else return b+sum(a,b-1);

}

ArrayArrayArray is a set of adjacent memory locations of the same data type. All of them have one name, which is the array name. each location has subscript number started by zero.

One Dimensional arrayOne Dimensional arrayData_Type array_name[How many elements] ;

Two Dimensional arrayTwo Dimensional arrayData_Type array_name[#Rows][#Columns] ;

One Dimensional arrayOne Dimensional arrayint List[5];

100 30 10 -20 5

List[0] List[1] list[2] list[3] list[4]

Read ElementsList[0] = 100;List[1] = 30;List[2] = 10;List[3] = -20;List[4] = 5;

Print Elementsfor(i=0; i<5; i++)

cout<<List[i];

Definitions and initial values

int X[4]={4,2,3,1}; int A[10]={0};int B[100]={1};int C[7]={1,2,6};int d[5];int E[ ]={4,6,2};

Not accepted Statements

int A[4]={4,2,4,5,2};int E[ ];int n=5; int X[n];

Corrected by:const int n=5;int X[n];


int A[5] = {10,20,15,100,30};

for (int i=0; i<5; i++)cout<<A[i]<<'\t';

for (i=0; i<5; i++) {cout<<"\nPlease Enter A["<<i<<"]:";cin>>A[i]; }

for (i=0; i<5; i++)cout<<A[i]<<'\t';

cout<<endl;}

#include <iostream.h>void main() { const int Size = 10; char KeyBSym[Size]={ ')', '!', '@', '#', '$', '%', '^', '&', '*', '(' }; for (int i=0; i<Size; i++) cout<<"Shift + number "<<i<<" Give Symbol "<<KeyBSym[i]<<endl;}

#include <iostream.h>const int S = 10;void main() {

int A[S];for(int i=0; i<S; i++) {

cout<<"\nEnter A["<<i<<"]:";cin>>A[i]; }

int PositiveSum = 0, EvenSum = 0,Gthan10_Count = 0;

for (i=0; i<S; i++) {if (A[i]>0)

PositiveSum += A[i];if (A[i]%2 == 0)

EvenSum += A[i];if (A[i]>10)

Gthan10_Count++;}cout<<"\nSummation of positive Elements: "<<PositiveSum;cout<<"\nSummation of Even Elements: "<<EvenSum;cout<<"\n# Element, which are greater than 10: "<<Gthan10_Count;cout<<endl;

}

#include <iostream.h>const int S = 10;void main() {

int A[S];for(int i=0; i<S; i++) {

cout<<"\nEnter A["<<i<<"]:";cin>>A[i]; }

long Even_Position_Mul = 1, Odd_Position_Mul = 1;for (i=0; i<S; i++)

if(i%2==0)Even_Position_Mul *= A[i];

elseOdd_Position_Mul *=A[i];

cout<<"\nMultiplication of elements at Even position: "<<Even_Position_Mul; cout<<"\nMultiplication of elements at Odd position: "<<Odd_Position_Mul; cout<<endl;}

Find the Maximum elementFind the Maximum element#include <iostream.h>const int Size = 10;void main() {

int Vector[Size];for(int i=0; i<Size; i++)

cin>>Vector[i];

for(i=0; i<Size; i++)cout<<Vector[i]<<'\t';

cout<<endl;

int Max = Vector[0];for(i=1; i<Size; i++)

if (Max<Vector[i])Max=Vector[i];

cout<<"\nMax= "<<Max<<endl;}

SearchSearch#include <iostream.h>const int Size = 10;void main() {


cin>>Vector[i];cout<<endl;

int Element;cout<<"What is the element that you looking for";cin>>Element;

bool Found = false;for(i=0; i<Size; i++)

if(Element = = Vector[i]){Found = true;break; }

cout<<endl;if (Found)

cout<<Element<<" Found at position "<<i<<endl;else

cout<<Element<<" is not in the array \n";}

Another version of search exampleAnother version of search example#include <iostream.h>const int Size = 10;void main() {

int Vector[Size];for(int i=0; i<Size; i++)cin>>Vector[i];cout<<endl;

int Element;cout<<"What is the element that you are looking for: ";cin>>Element;bool Found = false;for(i=0; i<Size; i++)if(Element == Vector[i]){cout<<Element<<" is found at position "<<i<<endl;Found=true; }

if (!Found)cout<<Element<<" is not in the array \n";

}

Sort the elements:Sort the elements:#include <iostream.h>const int Size = 5;void main() {


cin>>Vector[i];


cout<<endl;

for(i=0; i<Size - 1; i++)for(int j=i+1; j<Size; j++)

if (Vector[i]>Vector[j]) {int Temp = Vector[i];Vector[i] = Vector[j];Vector[j] = Temp;}


cout<<endl; }

build a swap function function

void swap(int & x,int & y){

int temp;temp=x;x=y;y=temp;

}

Bubble sort using the swap function

#include <iostream.h>void swap(int &,int &);const int Size = 5;

void main() {int Vector[Size];for(int i=0; i<Size; i++)cin>>Vector[i];

for(i=0; i<Size - 1; i++)for(int j=i+1; j<Size; j++)if (Vector[i]>Vector[j]) swap(Vector[i],Vector[j]);

for(i=0; i<Size; i++)cout<<Vector[i]<<'\t';cout<<endl; }

void swap(int & x,int & y){

int temp;temp=x;x=y;y=temp;

}

Arrays and Call by reference

• We can’t return the array using return statement.

• We need to use the call by reference technique.

• BUT when passing an array to a function, it is sent as call by reference.

• No need to declare it as int &[ ]

Write a function that return the sum of an array#include <iostream.h>

int Arr_Sum(int [ ],int);void main( ){

int A[5]={2,3,4,5,6};int B[4]={5,3,1,7};cout<<"The sum of A is "<<Arr_Sum(A,5)<<endl;cout<<"The sum of B is "<<Arr_Sum(B,4)<<endl;

}int Arr_Sum(int x[ ],int size){int S=0;for(int i=0;i<size;i++) S=S+x[ i ];return S;}

Functions to Read and print arrays

#include <iostream.h>void Arr_read(int [ ],int);void Arr_print(int[ ],int);void main(){

int A[5];int B[4];Arr_read(A,5);Arr_read(B,4);Arr_print(A,5);Arr_print(B,4);}

void Arr_read(int x[ ],int size){ for(int i=0;i<size;i++) {cout<<"Enter a number please "; cin>>x[i];}}

void Arr_print(int x[ ],int size){for(int i=0;i<size;i++) cout<<x[i]<<" ";cout<<endl;}

Function to calculate the sum of two arrays#include <iostream.h>

void sum(int [ ],int [ ],int[ ],int);void main(){int a[4]={4,3,2,1};int b[4]={2,2,4,4};int c[4];sum(a,b,c,4);Arr_print(c,4);}

void sum(int x[ ],int y[ ],int z[ ],int s) {for (int i=0;i<s;i++) z[i]=x[i]+y[i];}

cout statement with setw( )#include <iostream.h>#include <iomanip.h>void main(){for(int i=1; i<= 5;i++) // without using setw( ) cout<<i<<" "<<i*i<<" "<<i*i*i<<endl;

cout<<endl;

for(i=1; i<= 5;i++) // with using setw( ) cout<<setw(4)<<i<<setw(4)<<i*i<<setw(4)<<i*i*i<<endl;}

Strings#include <iostream.h>void main(){

char n[10];char a[10]={'A','h','m','e','d'};for(int i=0; a[i]!=0 ; i++)

cout<<a[i]<<endl;cout<<endl;

}

Q1 in the exam#include <iostream.h>void main(){

int a[4][3];for(int i=0;i<4;i++)

for(int j=0;j<3;j++){ cout<<"Enter a number "; cin>>a[i][j];}

for(int k=0;k<3;k++){

int s=0;for(int m=0;m<4;m++)

s=s+a[m][k];cout<<s<<endl;

}}

Two Dimensional arrayTwo Dimensional arrayint Matrix[3][4];

30

Assign values to ElementsMatrix[0][1] = 30;Matrix[1][0] = 100;Matrix[1][2] = 10;Matrix[2][3] = -20;Matrix[2][0]=Matrix[1][2];

Print Elementsfor(i=0; i<3; i++){ for(j=0; j<4; j++) cout<<Matrix[i][j]<<“\t”; cout<<endl; }

100 10

10 -20

0 1 2 3

0

1

2

int A[2][3] = { {1 ,2 , 3 },{10,20,30}};

int Matrix[3][4]= {{0,30 },{100,0,10},{0,0,0,-20}};


int A[2][3] = {{1,2,3},{10,20,30}};int B[2][3] = {100,200,300,40,50,60};int C[2][3] = {{15,25},{105,205}};for( int i=0; i<2; i++){

for( int j=0; j<3; j++)cout<<A[i][j]<<'\t';

cout<<endl; }cout<<endl;for( i=0; i<2; i++){

for( int j=0; j<3; j++)cout<<B[i][j]<<'\t';

cout<<endl; }cout<<endl;for( i=0; i<2; i++){

for( int j=0; j<3; j++)cout<<C[i][j]<<'\t';

cout<<endl; }}

#include <iostream.h>const int Rows = 3, Columns = 4;void main() {

int A[Rows][Columns];for (int i=0; i<Rows; i++)

for (int j=0; j<Columns; j++) {cout<<"\nEnter A["<<i<<"]["<<j<<"]:";cin>>A[i][j]; }

for (i=0; i<Rows; i++){for(int j=0; j<Columns; j++)

cout<<A[i][j]<<'\t';cout<<endl; }

}

#include <iostream.h>int A_sum(int [ ][2],int);void main(){

int x[3][2]={6,5,4,3,2,1};int y[4][2]={5,4,3,2,3,4,1};cout<<"The sum of the array x is “ <<A_sum(x,3)<<endl;cout<<"The sum of the array y is “ <<A_sum(y,4)<<endl;

}int A_sum(int a[ ][2],int r){

int s=0;for(int i=0;i<r;i++)

for(int j=0;j<2;j++)s=s+a[i][j];

return s;}

Find The sum of 2-D arrays using functions`

Diagonal SummationDiagonal Summation#include <iostream.h>const int Rows = 4, Columns = 4;void main() {



int DSum = 0;

for (i=0; i<Rows; i++)DSum += A[i][i];

cout<<"Diagonal Sum = "<<DSum<<endl;}

Inverse Diagonal SummationInverse Diagonal Summation#include <iostream.h>const int Rows = 4, Columns = 4;void main() {



int DSum = 0;for (i=0; i<Rows; i++)

for (int j=0; j<Columns; j++)if ( i+j= = 3)

DSum += A[i][j];cout<<"Diagonal Sum = "<<DSum<<endl;}

Lower Triangular MultiplicationLower Triangular Multiplication#include <iostream.h>const int Rows = 4, Columns = 4;void main() {



long LTmul = 1;

for (i=1; i<Rows; i++)for(int j=0; j<i; j++)

LTmul *= A[i][j];

cout<<"Lower Traingular Mul = "<<LTmul<<endl;}

Lower Triangular MultiplicationLower Triangular Multiplication#include <iostream.h>const int Rows = 4, Columns = 4;void main() {



long LTmul = 1;

for (i=0; i<Rows; i++)for(int j=0; j<Columns,; j++)

if (i>j) LTmul *= A[i][j];

cout<<"Lower Traingular Mul = "<<LTmul<<endl;}

Write a Program that copies an array to another

#include <iostream.h>const int R = 4, C= 3;void main() {

int A[R][C];int B[R][C];

for (int i=0; i<R; i++)for (int j=0; j<C; j++) {

cout<<"\nEnter A["<<i<<"]["<<j<<"]:";cin>>A[i][j]; }

for (i=0 ;i<R;i++) for(int j=0;i<C;j++) B[i][j]=A[i][j];

for (i=0; i<R; i++){for(int j=0; j<C; j++)

cout<<B[i][j]<<'\t';cout<<endl; }

}

Write a function that copies a 2-D array to another

void copyA(int x[ ][3],int y[ ][3],int r){for(int i=0;i<r;i++) for(int j=0;j<3;j++) y[i][j]=x[i][j];}

Write a Program that copies an array to another

#include <iostream.h>const int R = 4, C= 3;void main() {

int A[R][C];int B[R][C];

for (int i=0; i<R; i++)for (int j=0; j<C; j++) {

cout<<"\nEnter A["<<i<<"]["<<j<<"]:";cin>>A[i][j]; }

copyA(A,B,4);

for (i=0; i<R; i++){for(int j=0; j<C; j++)

cout<<B[i][j]<<'\t';cout<<endl; }

}

Store the following symbols in the Store the following symbols in the array Symbol.array Symbol. * $ $ $

# * $ $

# # * $

# # # * #include <iostream.h>const int Rows = 4, Columns = 4;void main() {

char Symbol[Rows][Columns];for (int i=0; i<Rows; i++)

for (int j=0; j<Columns; j++)if (i == j)

Symbol[i][j] = '*';else if (i > j)

Symbol[i][j] = '#';else

Symbol[i][j] = '$';for (i=0; i<Rows; i++){

for(int j=0; j<Columns; j++)cout<<Symbol[i][j];

cout<<endl; } }

Matrix Matrix SummationMatrix Matrix Summation#include <iostream.h>const int Rows = 4, Columns = 4;void main() {

int A[Rows][Columns], B[Rows][Columns], C[Rows][Columns];cout<<"\nEnter Matrix A elements:\n";for (int i=0; i<Rows; i++)

for( int j=0; j<Columns; j++)cin>>A[i][j];

cout<<"\nEnter Matrix B elements:\n";for (i=0; i<Rows; i++)

for( int j=0; j<Columns; j++)cin>>B[i][j];

for(i=0; i<Rows; i++)for(int j=0; j< Columns; j++)

C[i][j] = A[i][j] + B[i][j];for(i=0; i<Rows; i++){

for(int j=0; j<Columns; j++)cout<<C[i][j]<<'\t';

cout<<endl; }}

Write a function to add two Arrays

void add(int x[ ][4],int y[ ][4],int z[ ][4],int r){

}

Compute the average for 5 marks for 10 students

int marks [10][5];for(int i=0;i<10;i++) for(int j=0;j<5;j++){ cout<<“Enter mark”<<j+1<<“ for student”<<i+1;

cin>>marks[i][j];}float av[10];for(i=0;i<10;i++){ float sum=0;for(int j=0;j<5;j++) sum=sum+marks[i][j];av[i]=sum/5;} printing……

int A[3][4], B[4][3];for(int i=0;i<3;i++) for(int j=0;j<4;j++) cin>>A[i][j];for(i=0;i<3;i++) for(int j=0;j<4;j++) B[ j][i]=A[i][j]Printing B ……..

Function to calculate the Transpose of an array 3x4

void trans34(int x[3][4],int y[4][3]){for(int r=0;r<3;r++) for(int c=0;c<4;c++) y[c][r]=x[r][c];}

HomeworkHomework

1- Write program to compute and print the result of Matrix A[n][n] multiplied by Matrix B[n][n] and store the result within Matrix C[n][n].

2- Write program to Compute and print the result of Matrix A[n][n] multiplied by Vector V[n] and store the result within Vector C[n].

Calculate an accurate value for Pi

double Pi=0;for(int i=0;i<=1000;i++) if( i%2==0)

Pi=Pi+4.0/(2*i+1);else

Pi=Pi-4.0/(2*i+1);

double pi;int t=1;for(int i=1;i<=1000;i=i+2)

{ pi=pi+t*4.0/i;t=t*-1;

}

Strings

#include <iostream.h>void main(){

char n[10];char a[10]={'A','h','m','e','d'};for(int i=0; i<5 ; i++)

cout<<a[i]<<endl;}

#include <iostream.h>void main(){char a[10]={'I','b','r','a','h','e','e','m‘};for(int i=0; a[i]!=0 ; i++)

cout<<a[i]<<endl;}

#include <iostream.h>void main(){char a[10]={'A','h','m','e','d'};for(int i=0; a[i]!=0 ; i++){for(int j=0;j<i;j++)

cout<<" "; cout<<a[i]<<endl;}}

#include <iostream.h>void main(){char a[10]=“Ahmed“;for(int i=0; a[i]!=0 ; i++){for(int j=0;j<i;j++)

cout<<" "; cout<<a[i]<<endl;}}

#include <iostream.h>void main(){char a[10];cout<<"Enter a name : ";cin>>a;cout<<a<<endl;for(int i=0; a[i]!=0 ; i++){for(int j=0;j<i;j++)

cout<<' '; cout<<a[i]<<endl;}}

#include <iostream.h>void main(){char a[10];char b[10];cout<<"Enter ur first name : ";cin>>a;cout<<"Enter ur second name : ";cin>>b;cout<<"Hello "<<a<<" "<<b<<endl;for(int i=0; a[i]!=0 ; i++){for(int j=0;j<i;j++)

cout<<' '; cout<<a<<endl;}}

#include <iostream.h>void main(){char a[10];cout<<"Enter a name : ";cin>>a;cout<<a<<endl;for(int i=0; a[i]!=0 ; i++){for(int j=0;j<i;j++)

cout<<' '; cout<<a<<endl;}cout<<i<<endl;}

Final exam question

• Write a function that returns the length of a string or array of characters.

• The function prototype is• int length(char[ ]);

int length(char name[ ]){for(int i=0;name[i]!=0;i++);return i;}

#include <iostream.h>void main(){char name[10];

cout<<"Enter ur name : ";cin>>name;

for(int i=0; name[i]!=‘\0’ ; i++);

for(int j=i-1;j>=0;j--) cout<<name[j];

cout<<endl;

}

Write a program that prints the name inversed( from the last char to the first character

• See the prev. slide

Pointers

#include <iostream.h>void main(){int x=5;int* y; // pointer to an integery=&x;cout<<x<<endl<<&x<<endl;cout<<y<<endl<<*y<<endl;}

#include <iostream.h>void main(){char a[10]="Ahmad"; // prints Ahmedcout<<a<<endl;int b[10]={1,2,3,4,5};cout<<b<<endl; // prints the address of

//the first element in the array}

#include <iostream.h>void main(){char a[10]="Ahmad"; // prints Ahmedcout<<a<<endl;int b[10]={1,2,3,4,5};cout<<b<<endl; // prints the address of

//the first element in the arrayint x=5;int* y; // pointer to an integery=&x;cout<<x<<endl<<&x<<endl;cout<<y<<endl<<*y<<endl;}

1- do-while statement.2- nested for loop3- nested while statement4- math library functions.5- functions prototype and definitions.6- rand () and srand() functions7- scope rules (local, global and static variables)8- Recursion9- call by value and reference10- Inline function11- :: scope resolution operator.12- one dim array only ( definition and passing one dim array

to a function).

901131 Examples

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