Queue Reconstruction by Height

Similar Problems:

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]]

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.

// https://code.dennyzhang.com/queue-reconstruction-by-height // Basic Ideas: // Intuitive Idea: Find the mininum h, whose k is 0 // Once we have identified one, // we deduct k of other other items whose h is no smaller than current one // // Better Idea: sort and insert // // [[7,0], [4,4], [7,1], [5,0], [6,1], [5,2]] // // sorted: // [[7,0], [7,1], [6,1], [5,0], [5,2], [4,4]] // // switch: // [[7,0], [6,1], [7,1], [5,0], [5,2], [4,4]] // [[5,0], [7,0], [6,1], [7,1], [5,2], [4,4]] // [[5,0], [7,0], [5,2], [6,1], [7,1], [4,4]] // [[5,0], [7,0], [5,2], [6,1], [4,4], [7,1]] // // TODO: need a simple way to switch items // // Complexity: Time O(n^2), Space O(n) func reconstructQueue(people [][]int) [][]int { res := people sort.Slice(people, func(i, j int) bool { if people[i][0] > people[j][0] {return true} if people[i][0] == people[j][0] && people[i][1] < people[j][1] { return true } return false }) for i, p := range people { j := p[1] copy(res[j+1:i+1], res[j:i]) res[j] = p } return res }