plusOne

class Solution {
public:
    vector<int> plusOne(vector<int> &digits) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        bool plus = true;
        vector<int>::iterator iter = digits.end();
        iter--;
        while(plus&&iter>=digits.begin())
        {
            *iter += 1;
            if(*iter > 9)
            {
                *iter = 0;                
            }
            else
            {
                plus = false;
            }
            iter--;
        }
        if(plus)
        {
            digits.insert(digits.begin(),1);
        }
        return digits;
    }
};