(leetcode)Plus One

 1 class Solution {
 2 public:
 3     vector<int> plusOne(vector<int>& digit){
 4 //         int len = digit.size();
 5 //         long long res = 0;
 6 //         reverse(digit.begin(),digit.end());
 7 //         for(int j = len-1;j >= 0;--j)
 8 //         {
 9 //             res = res*10+ digit[j];
10 //         }
11 //         long long newres = res+1;
12 //         digit.clear();
13 //         while(newres!=0)
14 //         {
15 //             int a = newres%10;
16 //             digit.push_back(a);
17 //             newres /= 10;
18 //         }
19 //         reverse(digit.begin(),digit.end());
20 //         return digit;
21 
22         int carry = 0;
23         //reverse(digit.begin(),digit.end());
24         vector<int> newvec;
25         int len = digit.size();
26         for(int i=len-1;i>=0;--i)
27         {
28             int tmp;
29             if(i == len-1)
30             {
31                 tmp = digit[i] + 1;
32             }
33             else
34                 tmp = digit[i] + carry;
35             
36             carry = 0;
37             
38             if(tmp>=10)
39             {
40                 carry = 1;
41                 tmp=tmp%10;
42                 newvec.push_back(tmp);
43             } 
44             else
45             {
46                 newvec.push_back(tmp);
47             }
48             
49             if(i == 0 && carry == 1)
50             {
51                 newvec.push_back(carry);
52             }
53         }
54         reverse(newvec.begin(),newvec.end());
55         return newvec;
56     }
57 };