Last updated on July 18th, 2024 at 04:52 am

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

List of all LeetCode Solution

Topics

Companies

Bloomberg

Level of Question

Medium

Lexicographical Numbers LeetCode Solution

Problem Statement

Given an integer n, return all the numbers in the range [1, n] sorted in lexicographical order.

You must write an algorithm that runs in O(n) time and uses O(1) extra space. 

Example 1:
Input: n = 13
Output: [1,10,11,12,13,2,3,4,5,6,7,8,9]

Example 2:
Input: n = 2
Output: [1,2]

1. Lexicographical Numbers LeetCode Solution C++

class Solution {
public:
    void solve(int i, int n,vector<int> &v){
        if(i>n) return;
        v.push_back(i);
        for(int j=0;j<=9;j++){
            solve(i*10+j,n,v);
        }
    }
    vector<int> lexicalOrder(int n) {
        vector<int> ans;
        for(int i=1;i<10;i++){
            solve(i,n,ans);
        }
        return ans;
    }
};

2. Lexicographical Numbers Solution Java

class Solution {
    public List<Integer> lexicalOrder(int n) {
        List<Integer> list = new ArrayList<>();
        String[] str = new String[n];
        for(int i=1;i<=n;i++) str[i-1] = Integer.toString(i);
        Arrays.sort(str);
        for(String s: str) list.add(Integer.parseInt(s));
        return list;        
    }
}

3. Lexicographical Numbers Solution JavaScript

var lexicalOrder = function(n) {
    const a = new Array(n)
    for(let i = 0; i < n; i++){
        a[i] = i + 1;
    }
    return a.sort()    
};

4. Lexicographical Numbers Solution Python

class Solution(object):
    def lexicalOrder(self, n):
        top = 1
        while top * 10 <= n:
            top *= 10
        def mycmp(a, b, top=top):
            while a < top: a *= 10
            while b < top: b *= 10
            return -1 if a < b else b < a
        return sorted(xrange(1, n+1), mycmp)