Last updated on October 5th, 2024 at 04:49 pm

Here, We see Queue Reconstruction by Height LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

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Queue Reconstruction by Height LeetCode Solution

Problem Statement

You are given an array of people, people, which are the attributes of some people in a queue (not necessarily in order). Each people[i] = [h_i, k_i] represents the i^th person of height h_i with exactly k_i other people in front who have a height greater than or equal to h_i.

Reconstruct and return the queue that is represented by the input array people. The returned queue should be formatted as an array queue, where queue[j] = [h_j, k_j] is the attributes of the j^th person in the queue (queue[0] is the person at the front of the queue).

Example 1:
Input: people = [[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]]

Explanation:
Person 0 has height 5 with no other people taller or the same height in front.
Person 1 has height 7 with no other people taller or the same height in front.
Person 2 has height 5 with two persons taller or the same height in front, which is person 0 and 1.
Person 3 has height 6 with one person taller or the same height in front, which is person 1.
Person 4 has height 4 with four people taller or the same height in front, which are people 0, 1, 2, and 3.
Person 5 has height 7 with one person taller or the same height in front, which is person 1. Hence [[5,0],[7,0],[5,2],[6,1],[4,4],[7,1]] is the reconstructed queue.

Example 2:
Input: people = [[6,0],[5,0],[4,0],[3,2],[2,2],[1,4]]
Output: [[4,0],[5,0],[2,2],[3,2],[1,4],[6,0]]

1. Queue Reconstruction by Height LeetCode Solution C++

class Solution {
public:
    static bool comp(vector<int>& a, vector<int>& b){
        if(a[0] == b[0]) return a[1] < b[1];
        return a[0] > b[0];
    }
    vector<vector<int>> reconstructQueue(vector<vector<int>>& people) {   
        sort(people.begin(), people.end(), comp);
        vector<vector<int>> ans;
        for(auto man : people){
            ans.insert(ans.begin()+man[1], man);
        }
        return ans;
    }
};

2. Queue Reconstruction by Height LeetCode Solution Java

class Solution {
    public int[][] reconstructQueue(int[][] people) {
        Arrays.sort(people, (a,b) -> a[0] == b[0] ? a[1] - b[1] : b[0] - a[0]);
        List<int[]> ordered = new LinkedList<>();
        for (int[] p: people) ordered.add(p[1], p);
        return ordered.toArray(new int[people.length][2]);        
    }
}

3. Queue Reconstruction by Height Solution JavaScript

var reconstructQueue = function(people) {
    let res = []
    people.sort((a, b) => a[0] == b[0] ? a[1] - b[1] : b[0] - a[0])
    people.forEach(val => {
        res.splice(val[1], 0, val)
    })
    return res    
};

4. Queue Reconstruction by Height Solution Python

class Solution(object):
    def reconstructQueue(self, people):
        output=[]
        people.sort(key=lambda x: (-x[0], x[1]))                
        for a in people:
            output.insert(a[1], a)
        return output