hdu 2965组合数学题

类似于骨牌问题。我的做法就是首先看能不能横着排满，然后看能不能竖着排满，都不行的话就考虑一些横着排，一些竖着排，看能不能满足要求，最后也就转化为求ax+by=n有没有非负解的问题。可是我用扩展欧几里得打了，超时，无奈只能纯枚举了，枚举放1个、2个、3个...直到放不下为止。这说明测试数据很操蛋。

/*

 * hdu2965/win.cpp

 * Created on: 2012-11-4

 * Author    : ben

 */

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <cmath>

#include <ctime>

#include <iostream>

#include <algorithm>

#include <queue>

#include <set>

#include <map>

#include <stack>

#include <string>

#include <vector>

#include <deque>

#include <list>

#include <functional>

#include <numeric>

#include <cctype>

using namespace std;

typedef long long LL;

int gcd(int a, int b) {

    int r;

    while(b) {

        r = a % b;

        a = b, b = r;

    }

    return a;

}

inline bool judge2(int a, int b, int z) {

    int x = 1;

    while(a * x < z) {

        if((z - a * x) % b == 0) {

            return true;

        }

        x++;

    }

    return false;

}



inline bool judge(int x, int y, int n, int m) {

    int t = gcd(x, y);

    if(n % t != 0 || m % t != 0) {

        return false;

    }

    x /= t, y /= t, m /= t, n /= t;

    if(n % x == 0 && m % y == 0) {

        return true;

    }

    if(n % y == 0 && m % x == 0) {

        return true;

    }

    if(n % x == 0 && n % y == 0 && judge2(x, y, m)) {

        return true;

    }

    if(m % x == 0 && m % y == 0 && judge2(x, y, n)) {

        return true;

    }

    return false;

}

int get_int() {

    int res = 0, ch;

    while (!((ch = getchar()) >= '0' && ch <= '9')) {

        if (ch == EOF)

            return 1 << 30;

    }

    res = ch - '0';

    while ((ch = getchar()) >= '0' && ch <= '9')

        res = res * 10 + (ch - '0');

    return res;

}

int main() {

#ifndef ONLINE_JUDGE

    freopen("data.in", "r", stdin);

#endif

    int T, x, y, n, m;

    T = get_int();

    while(T--) {

        x = get_int();

        y = get_int();

        n = get_int();

        m = get_int();

        bool ret = judge(x, y, n, m);

        puts(ret ? "YES" : "NO");

    }

    return 0;

}