HackerRank

题意
给出一系列数字，判断其中哪三个数字可以构成一个三角形，如果有多个，输出周长最大的那个，如果没有输出 - 1

思路
数据较小，所有情况FOR一遍 判断一下

AC代码

#include <cstdio>
#include <cstring>
#include <ctype.h>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <deque>
#include <vector>
#include <queue>
#include <string>
#include <map>
#include <stack>
#include <set>
#include <numeric>
#include <sstream>

using namespace std;
typedef long long LL;

const double PI  = 3.14159265358979323846264338327;
const double E   = 2.718281828459;
const double eps = 1e-6;

const int MAXN = 0x3f3f3f3f;
const int MINN = 0xc0c0c0c0;
const int maxn = 50 + 5;
const int MOD  = 1e9 + 7;

LL a[maxn];

bool judge(LL b[])
{
    if (b[0] + b[1] > b[2])
        return true;
    return false;
}

int main()
{
    int n;
    cin >> n;
    LL b[3], ans[3];
    LL MAX = MINN;
    for (int i = 0; i < n; i++)
        scanf("%lld", &a[i]);
    sort(a, a + n);
    int i, j, k;
    for (i = 0; i < n; i++)
    {
        for(j = i + 1; j < n; j++)
        {
            for (k = j + 1; k < n; k++)
            {
                b[0] = a[i];
                b[1] = a[j];
                b[2] = a[k];
                sort(b, b + 3);
                if (judge(b))
                {
                    LL temp = b[0] + b[1] + b[2];
                    if (temp > MAX)
                    {
                        for (int l = 0; l < 3; l++)
                            ans[l] = b[l];
                        MAX = temp;
                    }
                }
            }
        }
    }
    if (MAX != MINN)
    {
        printf("%lld %lld %lld
", ans[0], ans[1], ans[2]);
    }
    else
        cout << -1 << endl;
}