Question

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]]

Difficulty:Medium

Category:Greedy

Analyze

Solution

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