Submission #39004219

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Source Code Expand

#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define op(x) ((x&1)?x+1:x-1)
#define odd(x) (x&1)
#define even(x) (!odd(x))
#define lc(x) (x<<1)
#define rc(x) (lc(x)|1)
#define lowbit(x) (x&-x)
#define mp(x,y) make_pair(x,y)
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
using namespace std;
const int MAXN=1010,MAXM=60;
int n,a[MAXN];
ll k,ans,rest;
int dp[MAXM][MAXN];

int main(){
	cin>>n>>k;
	rep(i,1,n)cin>>a[i];
	
	dp[0][0]=1;ans=0;
	rest=__builtin_popcountll(k);

	rep(i,0,51){
		if(k>>i&1)rest--;
		rep(j,0,1000)if(dp[i][j]){
			if(k>>i&1){
				rep(idx,1,n){
					int v=(j+a[idx]);
					if(odd(n) || !rest)ans ^= ((1LL<<i) * (v&1));
					dp[i+1][v>>1] ^= 1;
				}
			}else{
				if(odd(n) || !rest)ans^= ((1LL<<i) * (j&1));
				dp[i+1][j>>1] ^= 1;
			}
		}
	}

	cout<<ans<<endl;

    return 0;
}

Submission Info

Judge Result