LeetCode: Reverse Integer

Reverse digits of an integer.

Example1: x = 123, return 321
Example2: x = -123, return -321

   int reverse(int x) {  
     int sign = 1, res = 0;  
     if (x<0)sign = -1;  
     vector< int > v;  
     x=abs(x);  
   
     while(x)  
     {  
       v.push_back(x%10);  
       x = x/10;  
     }  
   
     for(decltype(v.begin()) it = v.begin(); it != v.end(); it++)  
     {  
       res = res*10 + (*it);  
     }  
   
     return (res*sign);  
   }