In this post, we are going to solve the 66. Plus One problem of Leetcode. This problem 66. Plus One is a Leetcode easy level problem. Let’s see code, 66. Plus One – Leetcode Solution.

We provide the solution to this problem in 3 programming languages i.e. Java, C++ & Python.

Problem

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].

Constraints

• 1 <= digits.length <= 100
• 0 <= digits[i] <= 9
• digits does not contain any leading 0’s.

Now, let’s see the code of 66. Plus One – Leetcode Solution.

Plus One – Leetcode Solution

66. Plus One – Solution in Java

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

66. Plus One – Solution in C++

class Solution {
public:
    vector<int> plusOne(vector<int>& digits) {
        int len = digits.size();
        for(int i=len-1; i>=0; i--){
            if(digits[i] != 9){
                digits[i]+=1;
                return digits;
            }else{
                digits[i] = 0;
            }
        }
        vector<int> arr(len+1);
        arr.insert(arr.begin(), 1);
        
        return arr;
    }
};

66. Plus One – Solution in Python

class Solution(object):
    def plusOne(self, digits):
        string =""
        result =[]
        for d in digits:
            string += str(d)
        i = int(string) + 1
        for w in str(i):
            result.append(w)
        return result
        

Note: This problem 66. Plus One is generated by Leetcode but the solution is provided by CodingBroz. This tutorial is only for Educational and Learning purpose.