Help me in solving XORDIF problem

help
,
1

My issue

plz help…

My code

#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
	int t;
	cin>>t;
	while(t--){
	    int a,b;
	    cin>>a>>b;
	    if(a==b){cout<<0<<endl;
	    continue;}
	    if(a<b) swap(a,b);
	    int setbit=-5;
	    int y=0;
	    for(int i=29;i>=0;i--){
	         y=1<<i;
	        if((a&y)!=(b&y)){
	            setbit=i;
	            break;
	        }
	        
	    }
	    int res=0;
	    for(int i=setbit-1;i>=0;i--){
	         int x=1<<i;
	        if((a&x)>0 && (b&x)==0 ||(a&x)==0 && (b&x)>0){
	            res+=x;
	        }
	       
	    }
	    cout<<y-res<<endl;
    }
	return 0;
}

Problem Link: XORDIF Problem - CodeChef

2

use binary search