제출 #1313968

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1313968		ulvix	XOR Sum (info1cup17_xorsum)	C++20	56 / 100	1665 ms	16056 KiB

xorsum

// #pragma GCC optimize("Ofast,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
#ifdef ULVI
    #include "debug.hpp"
#else
    #define db(...)
    #define dbv(v)
    #define line()
#endif
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define ff first
#define ss second
#define enld endl
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<ll,ll> pll;
const ll sz=2e5+100;
const ll lg=30;
const ll mod=1e9+7;
const ll inf=1e18;
template<class T>
using indexed_set=tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

void solve(){
    ll n;
    cin>>n;
    vector<ll> v(n);
    for(ll i=0;i<n;i++) cin>>v[i];
    ll ans=0;
    for(ll b=0;b<lg;b++){
        ll pw=(1ll<<b);
        vector<ll> a(n);
        ll cnt=0,cnt0=0,cnt1=0;
        for(ll i=0;i<n;i++){
            a[i]=v[i]&(pw-1);
            if(v[i]>>b&1) cnt1++;
            else cnt0++;
            if(a[i]>=(pw+1)/2) cnt++;
        }
        ll pt=0;
        sort(all(a));
        for(ll i=n-1;i>=1;i--){
            while(pt<i && a[pt]+a[i]<pw) pt++;
            if(pt<i) cnt+=i-pt;
            else break;
        }
        if((cnt+cnt0*cnt1)&1) ans|=pw;
    }
    cout<<ans<<'\n';
}

int main(){
    // freopen("input.txt","r",stdin);
    // freopen("output.txt","w",stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll t=1;
    // cin>>t;
    for(ll _=1;_<=t;_++){
        // cout<<"Scenario #"<<_<<":\n";
        solve();
    }
}

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