190. Reverse Bits

Reverse bits of a given 32 bits unsigned integer.

For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as00111001011110000010100101000000).

Follow up:
If this function is called many times, how would you optimize it?

Related problem: Reverse Integer

Credits:
Special thanks to @ts for adding this problem and creating all test cases.

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public class Solution {
    // you need treat n as an unsigned value
    public int reverseBits(int n) {
        int ret=0;
        for(int i=0;i<32;i++){ ret=ret<<1;
            if(n%2!=0)ret+=1;
           
            n=n>>1;
        }return ret;
    }
}