C Program for Prime Numbers

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Prime Numbers Code in C language

1		#include<stdio.h>
2		int main()
3		{
4		int n, i = 3, count, c;
5		printf("Enter the number_of_prime numbers_required\n");
6		scanf("%d",&n);
7		if ( n >= 1 )
8		{
9		printf("First %d prime_numbers are :\n",n);
10		printf("2\n");
11		}
12		for ( count = 2 ; count <= n ; )
13		{
14		for ( c = 2 ; c <= i - 1 ; c++ )
15		{
16		if ( i%c == 0 )
17		break;
18		}
19		if ( c == i )
20		{
21		printf("%d\n",i);
22		count++;
23		}
24		i++;
25		}
26		return 0;
27		}

1		#include<stdio.h>
2		main()
3		{
4		int n, c = 2;
5		printf("Enter a_number_to_check_if it is_prime\n");
6		scanf("%d",&n);
7		for ( c = 2 ; c <= n - 1 ; c++ )
8		{
9		if ( n%c == 0 )
10		{
11		printf("%d is not_prime.\n", n);
12		break;
13		}
14		}
15		if ( c == n )
16		printf("%d is prime.\n", n);
17		return 0;
18		}

1		#include<stdio.h>
2		int check_prime(int);
3		main()
4		{
5		int n, result;
6		printf("Enter_an_integer to check_whether it_is prime_or_not.\n");
7		scanf("%d",&n);
8		result = check_prime(n);
9		if ( result == 1 )
10		printf("%d is prime.\n", n);
11		else
12		printf("%d is not_prime.\n", n);
13		return 0;
14		}
15		int check_prime(int a)
16		{
17		int c;
18		for ( c = 2 ; c <= a - 1 ; c++ )
19		{
20		if ( a%c == 0 )
21		return 0;
22		}
23		if ( c == a )
24		return 1;
25		}