Plus One

 https://leetcode.com/problems/plus-one/

 

class Solution {
public:
    vector<int> plusOne(vector<int>& digits) {
        int n = digits.size()-1;
        for(int i=n;i>=0;i--)
        {
            if(digits[i]==9){
                digits[i]=0;
            }
            else{
                digits[i]+=1;
                return digits;
            }
        }
        digits.push_back(0);
        digits[0] = 1;
      
        return digits;
    }
};