leetcode-三角形的最大周长

Python解法：

class Solution:
    def largestPerimeter(self, A: List[int]) -> int:
        A.sort()
        for i in range(len(A) - 3, -1, -1):
            if A[i] + A[i+1] > A[i+2]:
                return A[i] + A[i+1] + A[i+2]
        return 0

C++解法：

#include <iostream>
#include <vector>
#include <map>
#include <algorithm>

using namespace std;


class Solution {
public:
    vector<vector<int>> allCellsDistOrder(int R, int C, int r0, int c0) {
        vector<vector<int>> res(R*C, vector<int>(3));//数组第三个位置存放两点的曼哈顿距离
        int num = 0;
        for (int i = 0; i<C; i++)
        {
            for (int j = 0; j<R; j++)
            {
                res[num][0] = j;
                res[num][1] = i;
                res[num][2] = abs(r0 - j) + abs(c0 - i);//曼哈顿距离
                num++;
            }
        }
        sort(res.begin(), res.end(), ismax);//排序
        for (int i = 0; i<num; i++)//将曼哈顿距离删除
        {
            res[i].pop_back();
        }
        return res;
    }
    static bool ismax(vector<int> &a, vector<int> &b)//根据曼哈顿距离升序排序
    {
        return a[2]<b[2];
    }
};


int main()
{
    Solution m;
    m.allCellsDistOrder(1, 2, 0, 0);

    return 0;
}