【HDOJ】1239 Calling Extraterrestrial Intelligence Again

这题wa了很多词，题目本身很简单，把a/b搞反了，半天才检查出来。

#include <stdio.h>
#include <string.h>
#include <math.h>

char isPrime[100001];

int main() {
    int i, j, q, p, maxi, maxj, max;
    double m, a, b, n, tmp1, tmp2;

    memset(isPrime, 1, sizeof(isPrime));
    isPrime[0] = isPrime[1] = 0;
    for (i=2; i<100001; ++i) {
        if (isPrime[i]) {
            for (j=i+i; j<100001; j+=i)
                isPrime[j] = 0;
        }
    }

    while (scanf("%lf %lf %lf", &m, &a, &b) != EOF) {
        if (m==0.0f && a==0.0f && b==0.0f)
            break;
        n = a/b;
        a = sqrt(m);
        b = sqrt(m/n);
        i = (int)floor(a);
        j = (int)floor(b);
        max = 0;
        for (p=j; p>=2; --p) {
            if ( !isPrime[p] )
                continue;
            if (p*i <= max)
                break;
            for (q=i; q>=2; --q) {
                if ( !isPrime[q] )
                    continue;
                tmp1 = p*q;
                tmp2 = q*1.0f/p;
                if (tmp1<=m && tmp2<=1 && tmp2>=n) {
                    if (tmp1 > max) {
                        max = tmp1;
                        maxj = p;
                        maxi = q;
                    }
                    break;
                }
            }
        }
        printf("%d %d
", maxi, maxj);
    }

    return 0;
}