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]]

---

class Solution {
    public int[][] reconstructQueue(int[][] people) {
        Arrays.sort(people, new Comparator<int[]>(){
            public int compare(int[] a, int[] b){
                return a[0] != b[0] ? -a[0] + b[0] :  a[1] - b[1];//a是int[],所以a[1]=int[][1]
            }
        });

        LinkedList<int[]> list = new LinkedList<>();//不用Integer[]，int[]也是类，可以用于泛型中
        for(int[] peo : people){
            list.add(peo[1], peo);//add(index, element);根据索引插入
        }
        for(int i = 0; i < people.length; i++){//或者用list.toArray();
            people[i] = list.get(i);
        }
        return people;
    }
}