7-reverse_integer.cpp

// Given a signed 32-bit integer x, return x with its digits reversed. 
// If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.
// Assume the environment does not allow you to store 64-bit integers (signed or unsigned).

class Solution {
public:
    int reverse(int x) {
        int rev=0;      
        while(x){
         if (rev>INT_MAX/10 || rev<INT_MIN/10) return 0; // overflow condition
         rev=rev*10+x%10; 
         x=x/10;     
        } 
        return int(rev);
    }
};