`
Simone_chou
  • 浏览: 192784 次
  • 性别: Icon_minigender_2
  • 来自: 广州
社区版块
存档分类
最新评论

Predict Outcome of the Game(数学)

    博客分类:
  • CF
 
阅读更多
C. Predict Outcome of the Game
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

There are n games in a football tournament. Three teams are participating in it. Currently k games had already been played.

You are an avid football fan, but recently you missed the whole k games. Fortunately, you remember a guess of your friend for these kgames. Your friend did not tell exact number of wins of each team, instead he thought that absolute difference between number of wins of first and second team will be d1 and that of between second and third team will be d2.

You don't want any of team win the tournament, that is each team should have the same number of wins after n games. That's why you want to know: does there exist a valid tournament satisfying the friend's guess such that no team will win this tournament?

Note that outcome of a match can not be a draw, it has to be either win or loss.

Input

The first line of the input contains a single integer corresponding to number of test cases t (1 ≤ t ≤ 105).

Each of the next t lines will contain four space-separated integers n, k, d1, d2 (1 ≤ n ≤ 1012; 0 ≤ k ≤ n; 0 ≤ d1, d2 ≤ k) — data for the current test case.

Output

For each test case, output a single line containing either "yes" if it is possible to have no winner of tournament, or "no" otherwise (without quotes).

Sample test(s)
input
5
3 0 0 0
3 3 0 0
6 4 1 0
6 3 3 0
3 3 3 2
output
yes
yes
yes
no
no
Note

Sample 1. There has not been any match up to now (k = 0, d1 = 0, d2 = 0). If there will be three matches (1-2, 2-3, 3-1) and each team wins once, then at the end each team will have 1 win.

Sample 2. You missed all the games (k = 3). As d1 = 0 and d2 = 0, and there is a way to play three games with no winner of tournament (described in the previous sample), the answer is "yes".

Sample 3. You missed 4 matches, and d1 = 1, d2 = 0. These four matches can be: 1-2 (win 2), 1-3 (win 3), 1-2 (win 1), 1-3 (win 1). Currently the first team has 2 wins, the second team has 1 win, the third team has 1 win. Two remaining matches can be: 1-2 (win 2), 1-3 (win 3). In the end all the teams have equal number of wins (2 wins).

 

       题意:

       给出 T(1 ~ 100000) 组 case,每个 case 给出 5 个数,表示一共有 n 场比赛,现在已经比赛了 k 场,一共有 3 个team,还给出 a 与 b,代表 1 队和 2 队的绝对差值,2 队和 3 队的绝对差值。问比赛结束后,能否出现 3 队一起平手的情况。

 

        思路:

        数学。设 1 队得分 x,2 队得分 y,3 队得分 z,故可以得出关系式:

        | x - y | = a;

        | y - z | = b;

        x + y + z = k;

        可以解出 4 种关系式,如果 x >= 0 && y >= 0 && z >= 0 则进行下一步判断:

        首先算出剩下的比赛场数 left = n - k,取 x ,y ,z 中的最大值,用 left -= (Max - x),left -= (Max - y),left -= (Max - z)使之三队平衡,最后判断 left 能否整除 3 即可得出答案。

        这么多个式子,只要满足其中一个就可以判断为 yes 了。

 

        AC:

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>

using namespace std;

typedef long long ll;

ll n, k, a, b;

bool check (ll x, ll y, ll z) {
    ll Max = max(x, max(y, z));
    ll nn = n - k;
    nn -= (Max - x);
    nn -= (Max - y);
    nn -= (Max - z);

    if (!nn) return true;
    if (nn < 0 || nn % 3) return false;

    return true;
}

int main() {

    int t;
    scanf("%d", &t);
    while (t--) {

        scanf("%I64d%I64d%I64d%I64d", &n, &k, &a, &b);

        int temp = 0;

        ll x, y, z;
        ll ans = k + a + b;
        if (ans >= 0 && !(ans % 3)) {
            x = ans / 3 - a;
            y = ans / 3;
            z = ans / 3 - b;
            if (x >= 0 && y >= 0 &&
                z >= 0 && check(x, y, z)) temp = 1;
        }

        ans = k + a - b;
        if (ans >= 0 && !(ans % 3)) {
            x = ans / 3 - a;
            y = ans / 3;
            z = ans / 3 + b;
            if (x >= 0 && y >= 0
                && z >= 0 && check(x, y, z)) temp = 1;
        }

        ans = k - a + b;
        if (ans >= 0 && !(ans % 3)) {
            x = ans / 3 + a;
            y = ans / 3;
            z = ans / 3 - b;
            if (x >= 0 && y >= 0
                && z >= 0 && check(x, y, z)) temp = 1;
        }

        ans = k - a - b;
        if (ans >= 0 && !(ans % 3)) {
            x = ans / 3 + a;
            y = ans / 3;
            z = ans / 3 + b;
            if (x >= 0 && y >= 0
                && z >= 0 && check(x, y, z)) temp = 1;
        }

        if (temp) printf("yes\n");
        else printf("no\n");
    }
    return 0;
}

 

 

 

 

分享到:
评论

相关推荐

Global site tag (gtag.js) - Google Analytics