Leetcode Plus One Problem Solution

In this Leetcode Plus One Problem Solution 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.

Problem solution in Python.

class Solution(object):
    def plusOne(self, digits):
        """
        :type digits: List[int]
        :rtype: List[int]
        """
        digits = "".join([str(i) for i in digits])
        cal = str(int(digits)+1)
        return [int(i) for i in cal]

Problem solution in Java.

public int[] plusOne(int[] digits) {
        for(int i=digits.length-1; i>=0; i--){
            if(digits[i]!=9){
                digits[i]++;
                break;
            }
            if(i==0){
                digits = new int[digits.length+1];
                digits[0]=1;
                return digits;
            }
            digits[i]=(digits[i]+1)%10;
        }
        return digits;
    }

Problem solution in C++.

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

Problem solution in C.

int* plusOne(int* digits, int digitsSize, int* returnSize){
    
    int originSize = digitsSize;
    for(int i = digitsSize-1; i>=0; i--){
        if(digits[i]==9){
            digits[i] = 0;
        }else{
            digits[i]++;
            break;
        }
    }
    if(digits[0] == 0){
        digitsSize++;
    }
    *returnSize = digitsSize;
    int* returnArr = (int*)malloc(digitsSize * sizeof(int));
    
    if(originSize == digitsSize){
        for(int i = digitsSize-1; i>=0; i--){
            returnArr[i] = digits[i];
        }    
    }else{
        for(int i = digitsSize-1; i>0; i--){
            returnArr[i] = digits[i-1];
        }
        returnArr[0] = 1;
    }
    
    return returnArr;
}