Submission #159309

#	Time	Username	Problem	Language	Result	Execution time	Memory
159309		mrtsima22	XOR Sum (info1cup17_xorsum)	C++17	0 / 100	1681 ms	8184 KiB

xorsum

#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=29;
int n,a[1000004],b[1000004];
int c[39],ans;
int main(){FAST;xRand;
for(int i=1;i<=M;i++){
	c[i]=(1<<i)-1;
}
cin>>n;
for(int i=0;i<n;i++){
	cin>>a[i];
}
for(int i=1;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;
	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(r2>=l2)
			k+=(r2-l2+1);
//		cout<<l1<<" "<<r1<<" "<<l2<<" "<<r2<<endl;
	}
	k/=2;
//	cout<<k<<" ";
	if(k&1)
		ans|=(1<<i);
//	cout<<ans<<endl;
}
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 (stderr)

xorsum.cpp:3:0: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
 #pragma GCC optimization ("unroll-loops")

• Subtask 1: 0 / 7
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 38
• Subtask 5: 0 / 23