Submission #4184414

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Source Code Expand

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

int n;

vector<int> v;

long long int ans=0;

set<int> mp;

int main(){
	cin>>n;
	for(int i=0;i<n;i++){
		int a;
		scanf("%d",&a);
		v.push_back(a);
		ans^=a;
		mp.insert(a);
	}
	//cout<<ans<<endl;
	int turn=0;
	int ans2=0;
	for(int i=31;i>=0;i--){
		//cout<<i<<" "<<(ans>>i)<<endl;
		int used=-1;
		if((turn^(ans>>i))&1){
			//cout<<"!! "<<i<<endl;
			if(mp.count(1<<i)==0){
				puts("-1");
				return 0;
			}
			ans2++;
			turn^=true;
			used=(1<<i);
		}
		mp.clear();
		int z=(1<<i)-1;
		vector<int> nex;
		for(auto el:v){
			if(used!=el){
				nex.push_back(el&z);
				mp.insert(el&z);
				continue;
			}
			used=-1;
		}
		v=nex;
	}
	cout<<ans2<<endl;
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:16:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a);
                 ^

Judge Result