LeetCode – Refresh – Plus One

 1 class Solution {
 2 public:
 3     vector<int> plusOne(vector<int> &digits) {
 4         int len = digits.size(), carry = 0;
 5         if (digits.size() == 0) return vector<int> ();
 6         vector<int> result(len+1, 0);
 7         digits[len-1]++;
 8         for (int i = len-1; i >= 0; i--) {
 9             result[i+1] = digits[i] + carry;
10             carry = result[i+1]/10;
11             result[i+1] %= 10;
12         }
13         if (carry) result[0] = 1;
14         else result.erase(result.begin());
15         return result;
16     }
17 };