题解 | #筛选法求素数#

#include <stdio.h>

int main() {
    int num = 0;
    while (scanf("%d", &num) != EOF) 
    { 
        int arr[100] = {0};
        for (int i = 0; i < num - 1; i++)
        {
            arr[i] = 2 + i;
        }

        int sum = 0;
        for (int i = 2; i < num;i++)
        {
            for (int j = num - 2; j > 0; j--)
            {
                if (arr[j] != 0 && arr[j] != i && arr[j] % i == 0)
                {
                    arr[j] = 0;
                    sum++;
                }
            }

        }

        for (int i = 0; i < num - 1; i++)
        {
            if (arr[i] != 0)
            {
                printf("%d ",arr[i]);
            }
            
        }
        printf("\n%d",sum);
        
    }
    return 0;
}