用埃拉托色尼筛网法求质数

#include <stdio.h>
#define N 150

int main(void)
{
        int i, j, p[N];

        for (i = 0; i < N; ++i)
                p[i] = 0;

        for (i = 2; i <= N; ++i)
        {
                if (p[i] == 0)
                        printf("%i ", i);

                for (j = i; i * j < N; ++j)
                        p[i*j] = 1;
        }

        printf("\n");

        return 0;
}