题解 | 筛选法求素数

#include <stdio.h>

int main()
{
	int n = 0;
	scanf("%d", &n);
	int arr[100] = { 0 };
	int i = 0;
	int count = 0;
	for (i = 0; i < n - 1; i++)
	{
		arr[i] = i + 2;
	}
	int j = 0;
	for (i = 0; i < n - 1; i++)
	{
		if (arr[i] != 0 && arr[i] > 2)
		{
			for (j = 2; j <= n; j++)
			{
				if (arr[i] % j == 0 && j != arr[i])
				{
					count++;
					arr[i] = 0;
					break;
				}
			}
		}
	}
	for (i = 0; i < n - 1; i++)
	{
		if (arr[i] != 0)
		{
			printf("%d ", arr[i]);
		}
	}
	printf("\n%d\n", count);
	return 0;
}