BZOJ2299 [HAOI2011]向量

就是等价于一个4个元2个方程判断解的存在性。。。

然后乱搞吧。。。（貌似叫裴蜀定理？）

 

/**************************************************************
    Problem: 2299
    User: rausen
    Language: C++
    Result: Accepted
    Time:148 ms
    Memory:804 kb
****************************************************************/
 
#include <cstdio>
#include <algorithm>
  
using namespace std;
typedef long long ll;
ll T, a, b, x, y, d;
  
inline ll read(){
    ll x = 0, sgn = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9'){
        if (ch == '-') sgn = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9'){
        x = x * 10 + ch - '0';
        ch = getchar();
    }
    return sgn * x;
}
  
ll gcd(ll a, ll b){
    return a ? gcd(b % a, a) : b;
}
  
bool check(ll a, ll b){
    return a % d == 0 && b % d == 0;
}
  
int main(){
    T = read();
    while (T--){
        a = read(), b = read(), x = read(), y = read();
        d = gcd(a, b) * 2;
        if (check(x, y) || check(x - a, y - b) || check(x - b, y - a) || check(x - a - b, y - a - b))
            printf("Y\n");
        else printf("N\n");
    }
    return 0;
}