406.md

406. Queue Reconstruction by Height

Suppose you have a random list of people standing in a queue. Each person is described by a pair of integers (h, k), where h is the height of the person and k is the number of people in front of this person who have a height greater than or equal to h. Write an algorithm to reconstruct the queue.

Note:
The number of people is less than 1,100.

Example

Input:
[[7,0], [4,4], [7,1], [5,0], [6,1], [5,2]]

Output:
[[5,0], [7,0], [5,2], [6,1], [4,4], [7,1]]

#解析

1. 首先将pair< first,second > 进行降序排列，first大的排前面，first一样大则second小的排前面。以Example为例，排序后为：[7,0], [7,1], [6,1], [5,0], [5,2], [4,4]。
2. 建一个临时的vector< pair< int, int > > tmp,遍历input，将pair插入tmp，插入索引为相应的second的值。

class Solution {
public:
    vector<pair<int, int>> reconstructQueue(vector<pair<int, int>>& people) {
        sort(people.begin(), people.end(),[](pair<int,int> p1, pair<int,int> p2){
            return p1.first > p2.first || (p1.first == p2.first && p1.second < p2.second);
        });
        vector<pair<int,int>> sol;
        for (auto person : people){
            sol.insert(sol.begin() + person.second, person);
        }
        return sol;
    }
};