```
public int reverseBits(int n) {
long m = (long) Math.pow(2, 31);
long res = 0;
for(;n!=0;n>>=1){
if ((n & 1) == 1)
res = res + m;
m /= 2;
}
return (int) res;
}
Submission Result: Time Limit Exceeded
Last executed input: 2147483648
```