Last updated on October 9th, 2024 at 10:13 pm

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

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Plus One LeetCode Solution

Problem Statement

You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0‘s.

Increment the large integer by one and return the resulting array of digits.

Example 1:

Input: digits = [1,2,3]
Output: [1,2,4]
Explanation: The array represents the integer 123.
Incrementing by one gives 123 + 1 = 124.
Thus, the result should be [1,2,4].

Example 2:

Input: digits = [4,3,2,1]
Output: [4,3,2,2]
Explanation: The array represents the integer 4321.
Incrementing by one gives 4321 + 1 = 4322.
Thus, the result should be [4,3,2,2].

Example 3:

Input: digits = [9]
Output: [1,0]
Explanation: The array represents the integer 9.
Incrementing by one gives 9 + 1 = 10.
Thus, the result should be [1,0].

1. Plus One Leetcode Solution C++

class Solution {
public:
    vector<int> plusOne(vector<int>& digits) {
        bool carry = true;
        for(int i=digits.size()-1; i >= 0 && carry; i--) {
            carry = (++digits[i]%=10) == 0;
        }
        if(carry) {
            digits.insert(digits.begin(), 1);
        }
        return digits;
    }        
};

2. Plus One Leetcode Solution Java

class Solution {
    public int[] plusOne(int[] digits) {
    for (int i = digits.length - 1; i >= 0; i--) {
	    if (digits[i] < 9) {
		    digits[i]++;
		    return digits;
	    }
	    digits[i] = 0;
    }
    digits = new int[digits.length + 1];
    digits[0] = 1;
    return digits;        
    }
}

3. Plus One Leetcode Solution JavaScript

var plusOne = function(digits) {
    const fromArray = digits.join(''); // get Digits out of Array
    const toInt = BigInt(fromArray) ; //Dont use parseInt, use BigInt instead :) 
    const addOne = toInt + 1n; // add one! 
    const result =  Array.from(String(addOne), Number); // return digits to array
    return result   
};

4. Plus One Solution Python

class Solution(object):
    def plusOne(self, digits):
        digits[-1] += 1
        for i in range(len(digits)-1, 0, -1):
            if digits[i] != 10:
                break
            digits[i] = 0
            digits[i-1] += 1
    
        if digits[0] == 10:
            digits[0] = 0
            return [1] + digits
        return digits