Program to print prime numbers up to n

Question:

To print the prime numbers up to the given limit.

Logic:

• Get the input length from the user.
• Then divide the number with all other numbers.
• If the number is divisible by more than two numbers and then it is the prime number.
• Then print all the prime numbers up to the given length.

Algorithm:

1. Get the input length from the user.
2. One number takes modulo division with all other numbers.
3. Then count how many times the number divisible by other.
4. If the count value less than two will represent the prime number.
5. Repeat step 2 to 4 up to the given length.

Program:

#include<stdio.h>
void main()
{
   int i,j,count,n,a;
   clrscr();
   printf("Enter the limit to print prime numbers:");
   scanf("%d",&n);
   printf("1");
   for(i=2;i<=n;i++)
   {
     for(j=2;j<=i;j++)
     {
	a=i%j;                //number takes modulus with all other numbers
	if(a==0)              //only the number divides with j
	{
	   count++;
	}
     }
     if(count<2)              //means that it can't divide's only with one number
     {
	printf("%5d",i);
     }count=0;                //initializes count for next numbers counting 
   }getch();
}