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++;
}