【leetcode】Plus One

 1 class Solution {
 2 public:
 3     vector<int> plusOne(vector<int> &digits) {
 4         // Start typing your C/C++ solution below
 5         // DO NOT write int main() function
 6         vector<int> ret(digits);
 7         reverse(ret.begin(), ret.end());
 8         
 9         int flag = 1;
10         for(int i = 0; i < ret.size(); i++)
11         {
12             ret[i] += flag;
13             flag = ret[i] / 10;
14             ret[i] %= 10; 
15         }
16         
17         if (flag == 1)
18             ret.push_back(1);
19         
20         reverse(ret.begin(), ret.end());
21         
22         return ret;
23     }
24 };