Question

找出100到999之间素数。是素数返回1不是素数返回0

Answer 1

#include <stdio.h>

#include <math.h>

int prime(int n) {

        int i,flag = 1;

        for(i = 2; i <= sqrt(n) && flag; ++i)

                flag = (n%i);

        return flag;

}

int main() {

        int i,cnt = 0;

        for(i = 100; i < 1000; ++i) {

                if(prime(i)) {

                        if(cnt && cnt % 10 == 0) printf("\n");

                        printf("%5d",i);

                        ++cnt;

                }

        }

        if(cnt%10) printf("\n");

        return 0;

}