[cf] 803 div2 A. XOR Mixup

Preface

$tag:$ violence Exclusive or
Portal :

The question

Given an array $A$, among $n-1$ The number is the original array , Another number $n-1$ XOR of numbers , Ask about any permutation given , What is the value of this number

Ideas

Because the array can be divided into two parts ,$n-1$ and $1$, Again because There must be a solution

So the XOR sum of the whole array is $0$, So just pick one

Mycode

void solve(){
    
	cin>>n;
	for(int i = 1;i<=n;i ++ ) cin>>a[i];
	
	for(int i = 1;i<=n;i++){
    
		int res =0  ;
		
		for(int j = 1; j <=n ; j++ ){
    
			if(i == j) continue;
			res ^= a[j];
		}
		
		if(res == a[i]){
    
			cout<<a[i]<<endl;
			return;
		}
	}
	
}