Reverse digits of an integer.
Example1: x = 123, return 321
Example2: x = -123, return -321
public class Solution { public int reverse(int x) { int v= Math.abs(x); if(v==0)return 0; int r=0; int previous=0; while(v>0){ previous=r; r=r*10+v%10; if(r/10!=previous)return 0; v=v/10; } return x>0?r:-r; } }