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]]


根据身高和序号重组队列

(h,k)  h表示身高，k表示这个人前面的高度大于或等于h的人数

   为了使插入操作不影响后续的操作，身高较高的学生应该先做插入操作，否则身高较小的学生原先正确插入的第 k 个位置可能会变成第 k+1 个位置。

   身高降序、k 值升序，然后按排好序的顺序插入队列的第 k 个位置中。

 

java：

class Solution {
    public int[][] reconstructQueue(int[][] people) {
        if (people == null || people.length == 0 || people[0].length == 0){
            return new int[0][0] ;
        }
        Arrays.sort(people,(a,b) -> (a[0] == b[0] ? a[1] - b[1] : b[0] - a[0]));
        List<int[]> list = new ArrayList<>() ;
        for(int[] p : people){
            list.add(p[1] , p) ;
        }
        return list.toArray(new int[list.size()][]) ;
    }
}