66. Plus One

/**
 * Problem: LeetCode 66 - Plus One
 * Difficulty: Easy
 * Language: Java
 * Author: CodeByTushu
 */
class Solution {
    public int[] plusOne(int[] digits) {
        int n = digits.length;
        // Traverse digits from right to left
        for (int i = n - 1; i >= 0; i--) {
            if (digits[i] < 9) {
                digits[i]++;
                return digits;
            }
            digits[i] = 0;
        }
        // If all digits were 9 (e.g. 99 -> 100)
        int[] result = new int[n + 1];
        result[0] = 1;
        return result;
    }
}

"""
Problem: LeetCode 66 - Plus One
Difficulty: Easy
Language: Python
Author: CodeByTushu
"""
from typing import List

class Solution:
    def plusOne(self, digits: List[int]) -> List[int]:
        n = len(digits)
        # Traverse digits from right to left
        for i in range(n - 1, -1, -1):
            if digits[i] < 9:
                digits[i] += 1
                return digits
            digits[i] = 0
        # If all digits were 9 (e.g. 99 -> 100)
        return [1] + [0] * n

/**
 * Problem: LeetCode 66 - Plus One
 * Difficulty: Easy
 * Language: C++
 * Author: CodeByTushu
 */
#include <vector>

using namespace std;

class Solution {
public:
    vector<int> plusOne(vector<int>& digits) {
        int n = digits.size();
        // Traverse digits from right to left
        for (int i = n - 1; i >= 0; i--) {
            if (digits[i] < 9) {
                digits[i]++;
                return digits;
            }
            digits[i] = 0;
        }
        // If all digits were 9 (e.g. 99 -> 100)
        vector<int> result(n + 1, 0);
        result[0] = 1;
        return result;
    }
};

/**
 * Problem: LeetCode 66 - Plus One
 * Difficulty: Easy
 * Language: JavaScript
 * Author: CodeByTushu
 */
/**
 * @param {number[]} digits
 * @return {number[]}
 */
var plusOne = function(digits) {
    const n = digits.length;
    // Traverse digits from right to left
    for (let i = n - 1; i >= 0; i--) {
        if (digits[i] < 9) {
            digits[i]++;
            return digits;
        }
        digits[i] = 0;
    }
    // If all digits were 9 (e.g. 99 -> 100)
    const result = new Array(n + 1).fill(0);
    result[0] = 1;
    return result;
};