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]]
分析:https://leetcode.com/problems/queue-reconstruction-by-height/discuss/89345/Easy-concept-with-PythonC%2B%2BJava-Solution
- Pick out tallest group of people and sort them in a subarray (S). Since there's no other groups of people taller than them, therefore each guy's index will be just as same as his k value.
- For 2nd tallest group (and the rest), insert each one of them into (S) by k value. So on and so forth.
E.g.
input: [[7,0], [4,4], [7,1], [5,0], [6,1], [5,2]]
subarray after step 1: [[7,0], [7,1]]
subarray after step 2: [[7,0], [6,1], [7,1]]
1 public class Solution { 2 public int[][] reconstructQueue(int[][] people) { 3 Arrays.sort(people, (a, b) -> a[0] == b[0] ? a[1] - b[1] : b[0] - a[0]); 4 List<int[]> list = new LinkedList<>(); 5 for (int[] p : people) { 6 list.add(p[1], p); 7 } 8 return list.toArray(new int[list.size()][]); 9 } 10 }