Prime, reverse,power Programs in C Programming

Prime Number

Prime Number is a number that is divisible by 1 or itself. Negative numbers, zero, and one are not prime numbers.

Program 1: Write a program that prints a number to be a prime number or not.

#include<stdio.h>

int main()

{

int n,y,z,ep;

Printf("Enter a number:");

Scanf("%d",&n); 

if(n<=1)

{

Printf(%d is neither prime number or composite number",n);

return 0;

}

ep=n/2;

z=0;

y=2;

While(y<=ep)

{

if(n%y == 0)

{

z=1;

break;

}

y++;

}

if(z==0)

{

Printf("%d is a prime number",n); 

}

else

{

Printf("%d is not a prime number",n);

}

return 0;

}

Program 2: Write a prime number program that prints all the prime numbers starting from 5 to 20.

#include<stdio.h>

int main()

{

int n,y,z,ep;

Printf("Enter a number:");

Scanf("%d",&n); 

if(n<=1)

{

Printf(%d is neither prime number or composite number",n);

return 0;

}

if(s<=1)

{

n=2;

}

else

{

n=s;

}

While(n<=e)

{

ep=n/2;

z=0;

y=2;

While(y<=ep)

{

if(n%y == 0)

{

z=1;

break;

}

y++;

}

if(z==0)

{

Printf("%d\n",n); 

}

n++;

}

return 0;

}

 

Program 3: Write a program to accept a number and count digits.

#include<stdio.h>

int main()

{

int x, num, dc;

printf("Enter a number:");

Scanf("%d",&x);

if(x<0)

{

num=x*(-1);

}

else

{

num=x;

}

dc=1;

While(num>9)

{

dc++;

num=num/10;

}

Printf("Number of digits in %d are %d",x,dc);

return 0;

}

Program 4: Write a program to reverse a number

 #include<stdio.h>

int main()

{

int x,num,j;

Printf("Enter the number to reverse:");

Scanf("%d",&x); 

if(x<0)

{

j=x(-1);

}

else

{

j=x;

}

num=0;

While(j>0)

{

num=(num*10)+(j%10);

j=j/10;

}

if(x<0)

{

num=num(-1);

}

Printf("%d reversed is %d\n",x,num);

return 0;

}

Snippet for the Power Program(Exponent and Base will be input from keyboard)

int j=1;int result=1;

While(j<=exp)

{

result=result*base;

j++;

}