Computer and Information Technology notes: c program

C program to swap two numbers

#include< stdio.h >
#include< conio.h >
void main ()
{
int p, q, swap;
clrscr();
printf("Enter two numbers:");
scanf("%d\t %d",&a,&b);
swap=p; p=q; q=swap;
printf("After swapping the values are p=%d and q=%d",p,q);
getch();
}
}

OUTPUT :

Enter two numbers :5 8
After swapping the values are p=8 and q=5

C program to calculate the square of a number

# include< stdio.h >
# include< conio.h >
void main ()
{
int x, y;
clrscr();
printf(" Enter a number : ");
scanf("%d",&x);
y=x*x ;
printf(" The square of %d is %d",x,y);
getch();
}

OUTPUT :

Enter a number : 5
The square of 5 is 25

C program to display reverse of a number

#include< stdio.h >
#include< conio.h >
void main ()
{
int n , d1, d2;
clrscr();
printf(" Enter a number : ");
scanf("%d",&n);
d1=n%10 ;
n=n/10 ;
d2=n%10 ;
printf("Reversed no is %d%d",d1,d2);
getch();
}

OUTPUT :

Enter a number :25
Reversed no is 52

C program to calculate area and perimeter of a rectangle with given parameters

# include< stdio.h >
# include< conio.h >
void main ()
{
float l, b, a, peri;
clrscr();
printf(" Enter the length and breadth of the rectangle : ");
scanf("\n%f\n%f",&l,&b);
a = l * b;
peri = 2* (l + b);
printf(" The area of rectangle is= %f and its perimeter is = %f",a, peri);
getch();
}

OUTPUT :

Enter the length and breadth of the rectangle :
5
4
The area of rectangle is= 20 and its perimeter is = 18

C program to calculate the product of two number

#include< stdio.h >
#include< conio.h >
void main ()
{
int x, y, z;
clrscr();
printf(" Enter two numbers : ");
scanf("\n%d\n%d",&x,&y);
z=x*y ;
printf(" The product of given numbers is %d",z);
getch();
}

OUTPUT :

Enter two numbers :
5
4
The product of given numbers is 20

C program to find whether the given number is prime number or not

#include< stdio.h >
#include< conio.h >
void main()
{
int i=2,num;
clrscr();
printf("Enter a number:");
scanf("%d",&num);
while(num%i!=0)
{
i++;
}
if(num==i)
{
printf("The number %d is a prime Number",num);
}
else
{
printf("The number %d is not a prime number",num);
}
getch();
}

OUTPUT :

Enter a number :13
The number 13 is a prime Number

OR

OUTPUT :

Enter a number :12
The number 12 is not a prime Number

C program to display the month name

#include< stdio.h >
#include< conio.h >
void main()
{
int month;
clrscr();
printf("Enter a month number:");
scanf("%d",&month);
switch(month)
{
case 1:printf("January");
break;
case 2:printf("February");
break;
case 3:printf("March");
break;
case 4:printf("April");
break;
case 5:printf("May");
break;
case 6:printf("June");
break;
case 7:printf("July");
break;
case 8:printf("August");
break;
case 9:printf("September");
break;
case 10:printf("October");
break;
case 11:printf("November");
break;
case 12: printf("December");
break;
default:printf("Invalid month number");
}
getch();
}

OUTPUT :

Enter a month number :12
December

OR

OUTPUT :

Enter a month number :15
Invalid month number

C program to find the lcm of two numbers

#include< stdio.h >
#include< conio.h >
void main()
{
int num1,num2,lcm;
clrscr();
printf("Enter two numbers:");
scanf("%d\t %d",&num1,&num2);
if (num1>num2)
lcm=num1;
else
lcm=num2;
while(lcm%num1!=0 || lcm%num2!=0)
{
lcm++;
}
printf("LCM= %d",lcm);
getch();
}

OUTPUT :

Enter two numbers: 2 4
LCM=2

C program to find GCD and LCM of given numbers

#include< stdio.h >
#include< conio.h >
void main()
{
int n1,n2,lcm,gcd;
clrscr();
printf("Enter two numbers:");
scanf("%d %d",&n1,&n2);
if (n1>n2)
{
lcm=n1;
gcd=n2;
}
else
{
lcm=n2;
gcd=n1;
}
while(lcm%n1!=0 || lcm%n2!=0)
{
lcm++;
}
while(n1%gcd!=0 || n2%gcd!=0)
{
gcd--;
}
printf("LCM= %d \nGCD=%d",lcm,gcd);
getch();
}

OUTPUT :

Enter a month number :12
December

OR

OUTPUT :

Enter a month number :15
Invalid month number

C program to find Multiplication table of a number

#include< stdio.h >
#include< conio.h >
void main()
{
int i,n;
void pro(int n);
clrscr();
printf("Enter a number: ");
scanf("%d",&n);
pro(n);
getch();
}
void pro(int n)
{
int i;
for(i=1;i<=10;i++)
{
printf("%d X %d = %d\n",n,i,(n*i));
}
}

OUTPUT :

Enter a number :
2 X 1 = 2
2 X 2 = 4
2 X 3 = 6
2 X 4 = 8
2 X 5 = 10
2 X 6 = 12
2 X 7 = 14
2 X 8 = 16
2 X 9 = 18
2 X 10 = 20

C program to find sum of n numbers using recursion

#include< stdio.h >
#include< conio.h >
void main()
{
int n,sum;
int recursion (int n);
clrscr();
printf("Enter a number:");
scanf("%d",&n);
S=recursion(n);
printf("Sum of numbers from 1 to %d is %d",n,S);
getch();
}
int recursion (int n)
{
if(n==1)
return 1;
else
return (n + recursion (n-1));
}

OUTPUT :

Enter a number : 5
Sum of numbers from 1 to 5 is 15

C program to find whether the given number is Armstrong or not : (e.g: 153= 1ᶾ + 5ᶾ + 3ᶾ = 153 )

#include< stdio.h >
#include< conio.h >
void main()
{
int sum=0,digit,n,temp;
clrscr();
printf("Enter a number:");
scanf("%d",&n);
temp=n;
while(n!=0)
{
digit=n%10;
sum=sum+digit*digit*digit;
n=n/10;
}
if(sum==temp)
{
printf("The number %d is an Armstrong Number",n);
}
else
{
printf("The number %d is not an Armstrong Number",n);
}
getch();
}

OUTPUT :

Enter a number :153
The number 153 is an Armstrong Number

OR

OUTPUT :

Enter a number :152
The number 152 is not an Armstrong Number

C program to calculate the average of three numbers

#include< stdio.h >
#include< conio.h >
void main ()
{
int a, b, c, S;
float Avg;
clrscr();
printf("Enter three numbers:");
scanf("%d\t %d\t %d",&a,&b,&c);
S= a+b+c ;
Avg=S/3.0 ;
printf(" The average of given numbers is equal to :%f",Avg);
getch();
}

OUTPUT :

Enter three numbers :2 5 8

The average of given numbers is equal to :5