Write a C program to print the prime numbers between 1 to 100.

If a number has only two factors, 1 & itself, then that number known as Prime Number. In others words, we can say that, a prime no cannot be divided by any numbers between 2 and [that number -1]. As a number cannot be divided by the any number which greater than its half. That is if a number not divide by the number between 2 and half of its numbers, then that number known as prime numbers.

As we know matematically 1 is not a prime number. we create a loop from 2 to 100. Now check each number for prime number. if it is a prime no then print it.

void main()
{
	int N=100,i,d,j,fl;
	clrscr();
	for(i=2;i<=N;i++)
	{
		fl=1;
		for(d=2;d<=i/2;d++)
		{
		     if(i%d==0)
		     {
			fl=0;
			break;
		     }
		}
		if(fl)
		{
			printf("%d  ",i);
		}
	}
}

Output

2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97