Java : T.C= O(r-l), Using properties of Bitwise operation. All-Correct

public static int maximizingXor(int l, int r) {

int max=Integer.MIN_VALUE;


int a,b;

a=l;

for(int i=l;i<r;i++)
 {
b=i+1;

if(a!=b)
    {
        if((a^b) > max)
        max=a^b;
     }
// assign a=b

b=a^b;
a=a^b;
}
        return max;
        }

}