Reverse digits of an integer.

 1 class Solution {
 2 public:
 3     int reverse(int x) {
 4         bool isPositive = true;
 5         if(x<0){
 6             isPositive = false;
 7             x = -x;
 8         }
 9         int y = 0;
10         while(x>0){
11            int tmp = x %10;
12            x = x / 10;
13            y = 10 * y +tmp;
14         }
15         if(!isPositive)
16             y = -y;
17          return y;
18     }
19 };