#pragma GCC optimize "-O3"
#pragma GCC optimize("Ofast")
#pragma GCC optimization ("unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
#define NumberOfOnes __builtin_popcount
#define LSOne(S) (S & (-S))
#define ll long long
#define two pair<int,int>
#define twoll pair<ll,ll>
#define four pair<two,two>
#define pb push_back
#define eb emplace_back
#define mk make_pair
#define y1 y1922
#define INF 1000000000000000000
#define P 1000000007
#define lmax 1000000000
#define nn 1000003
#define ff first.first
#define fs first.second
#define sf second.first
#define ss second.second
#define f first
#define s second
#define vi vector<int>
#define vll vector<ll>
#define vtwo vector<two>
#define ALL(container) (container).begin(), (container).end()
#define sz(container) (int)(container.size())
#define max(a,b) ((a)>(b)?(a):(b))
#define min(a,b) ((a)<(b)?(a):(b))
#define mid(a,b) (a+b>>1)
#define minN 0
#define maxN 10000000
#define na(x) ((x)<P?(x):(x)-P)
#define ab(a) (-(a)<(a)?(a):-(a))
#define FAST std::ios::sync_with_stdio(false)
#define xRand mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
#define rnd rng
#define IT iterator
typedef
tree<
int,// aq pair<int,int> shegidzlia
null_type,
less/*_equal*/<int>,// aqac
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
// '_equal' mashin ginda roca multiset gchirdeba
template<class key, class value,class cmp = std::less<key>>
using ordered_map = tree<key, value, cmp, rb_tree_tag, tree_order_statistics_node_update>;
ordered_map<int, int> my_map;
inline int rin(){
int x=0,w=1;char ch=getchar();
while ((ch<'0'||ch>'9')&&ch!='-') ch=getchar();
if (ch=='-') w=0,ch=getchar();
while (ch>='0'&&ch<='9') x=(x<<3)+(x<<1)+ch-'0',ch=getchar();
return w?x:-x;
}
inline int bin(){
int x=0;char ch=getchar();
while (ch<'0'||ch>'9') ch=getchar();
while (ch>='0'&&ch<='9') x=(x<<3)+(x<<1)+ch-'0',ch=getchar();
return x;
}
const int M=6;
int n,a[1000004],b[1000004];
int c[39],ans;
int main(){FAST;xRand;
for(int i=0;i<=M;i++){
c[i]=(1<<(i))-1;
}
cin>>n;
for(int i=0;i<n;i++){
cin>>a[i];
}
for(int i=0;i<=M;i++){
for(int j=0;j<n;j++){
b[j]=c[i]&a[j];
}
sort(b,b+n);
int l1=0,r1=n-1,l2=0,r2=n-1;
int k=0,K=0;
for(int o=0;o<n;o++){
while(l1<n&&b[o]+b[l1]<(1<<(i-1))) l1++;
while(r1>0&&b[o]+b[r1]>(1<<(i))-1) r1--;
while(l2<n&&b[o]+b[l2]<((1<<(i-1))+(1<<(i)))) l2++;
while(r2>0&&b[o]+b[r2]>((1<<(i+1))-2)) r2--;
if(r1>=l1){
k+=(r1-l1+1);
if(o<=r1&&o>=l1) K++;
}
if(r2>=l2){
k+=(r2-l2+1);
if(o<=r2&&o>=l2) K++;
}
// cout<<l1<<" "<<r1<<" "<<l2<<" "<<r2<<endl;
}
if(k&1){
k=2;
K=0;
}
k-=K;
k/=2;
k+=K;
// cout<<k<<" "<<K<<" ";
if(k&1)
ans|=(1<<(i));
// cout<<ans<<endl;
}
int k=0;
for(int i=0;i<n;i++){
if(a[i]&1) k++;
}
if(k&1) ans|=1;
cout<<ans<<endl;
}
/*
https://www.quora.com/How-can-I-solve-the-problem-XOR-sum-from-the-infO-1-Cup-2017-International-Round
*/
Compilation message
xorsum.cpp:3:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
#pragma GCC optimization ("unroll-loops")
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
356 ms |
8396 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
356 ms |
8396 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
