LeetCode 406. Queue Reconstruction by Height (Medium)

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]]

方法：sort + array
思路：把people按照身高从高到底排序，如果有两个人相同身高，那么按照the number of people infront of this person 从少到多排序。把排完序的people按照顺序插入到最后应该返回的数组中。
time complexity: O(n^2)(每次insert需要o(n)) space complexity: o(n)

class Solution:
    def reconstructQueue(self, people: List[List[int]]) -> List[List[int]]:
        if not people or len(people) == 0: return [] 
        
        people.sort(key=lambda x: (-x[0], x[1]))
        
        queue = []
        
        for p in people:
            queue.insert(p[1], p)
            
        return queue