根据身高重建队列

一、从前向后考虑

class Solution {


public:
    static bool cmp(vector<int> A, vector<int> B){
        return A[0] < B[0];
    }
    vector<vector<int>> reconstructQueue(vector<vector<int>>& people) {
        vector<vector<int>> queue;

        // 排序
        sort(people.begin(), people.end(), cmp);

        int len = 0;

        vector<vector<int>> raw = people;

        while(len < people.size()){
            int index = -1;
            for(int i = 0; i < people.size(); i++){
                if(index == -1 && people[i][1] == 0){
                    index = i;
                    queue.push_back(raw[index]);
                    people[i][1]--;
                } 
                if(index == -1 || people[i][0] == people[index][0]) people[i][1]--;
            }
            len++;
        }

        return queue;
    }
};

二、从后向前考虑

class Solution {

public:
    static bool cmp(vector<int> A, vector<int> B){
        if(A[0] == B[0]) return A[1] < B[1];
        return A[0] > B[0];
    }

    vector<vector<int>> reconstructQueue(vector<vector<int>>& people) {
        vector<vector<int>> queue;

        // 排序
        sort(people.begin(), people.end(), cmp);

        list<vector<int>> list_p;
        for(int i = 0; i < people.size(); i++){
            // 查找位置
            auto t = list_p.begin();
            int n = people[i][1];
            while(n){
                n--;
                t++;
            }
            list_p.insert(t , people[i]);
        }

        return vector<vector<int>>(list_p.begin(), list_p.end());
    }
};