HDU - 5655 CA Loves Stick

1.题面

http://acm.hdu.edu.cn/showproblem.php?pid=5655

2.题意

给你四个木棍的长度，问你这四根木棍能不能组成一个四边形。

3.思路

四边形成立的条件比较简单，就是任意三边之和大于第四边。

但是这道题目有两个坑。

一是输入的四条边中可能会出现长度为0的边。

二是四个数据都比较大，直接加减都容易爆long long。我的解决方案是使用unsighed long long，sort后判断a[0]+a[1] < a[2] + a[3]。

4.代码

/*****************************************************************    > File Name: tmp.cpp    > Author: Uncle_Sugar    > Mail: [e-mail]    > Created Time: 2016年04月02日 星期六 19时04分08秒*****************************************************************/# include <cstdio># include <cstring># include <cmath># include <cstdlib># include <climits># include <iostream># include <iomanip># include <set># include <map># include <vector># include <stack># include <queue># include <algorithm>using namespace std;const int debug = 1;const int size  = 5000 + 10; const int INF = INT_MAX>>1;typedef unsigned long long ll;int main(){    std::ios::sync_with_stdio(false);cin.tie(0);    int i,j;    int T;    cin >> T;    while (T--){        ll r[4];        for (i=0;i<4;i++){            cin >> r[i];        }        sort(r,r+4);        if (r[0]>0&&r[0]+r[1]>r[3]-r[2])            cout << "Yes\n";        else             cout << "No\n";    }    return 0;}