Reverse bits of a given 32 bits unsigned integer.

For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110000010100101000000).

public class Solution {
    // you need treat n as an unsigned value
    public int reverseBits(int n) {
        int result = 0;
        int mask =1;
        for(int i = 0 ;i<32;i++)
        {
            result|=((n&mask)<<(31-i));
            n>>=1;
            if(n==0)
                break;
        }
        return result;
    }
}