Submission #232154

#	Time	Username	Problem	Language	Result	Execution time	Memory
232154		VEGAnn	XOR Sum (info1cup17_xorsum)	C++14	45 / 100	1687 ms	8428 KiB

xorsum

#include <bits/stdc++.h>
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("fast-math")
//#pragma GCC optimize("no-stack-protector")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define PB push_back
#define MP make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pil pair<int, ll>
#define pli pair<ll, int>
#define pdd pair<ld, ld>
#define ft first
#define sd second
using namespace std;
using namespace __gnu_cxx;
using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
template<class T>
using ordered_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
const int N = 1000100;
const int M = 100100;
const int BIG = int(5e6);
const int oo = 2e9;
const ll OO = 1e18;
const int md = 998244353;
const int PW = 30;
ll sum;
vector<int> vc;
int a[N], ans = 0, n, mask, mn, mx;

void calc(int x){
    int fi = lower_bound(all(vc), mn - x) - vc.begin();
    int se = upper_bound(all(vc), mx - x) - vc.begin() - 1;

    sum += se - fi + 1;
}

int main() {
#ifdef _LOCAL
    freopen("in.txt","r",stdin); //freopen("output.txt","w",stdout);
#else
//    freopen("mining.in","r",stdin); freopen("mining.out","w",stdout);
    ios_base::sync_with_stdio(0); cin.tie(0);
#endif

    cin >> n;

    for (int i = 0; i < n; i++)
        cin >> a[i];

    for (int bt = 0; bt < PW; bt++){
        vc.clear();

        mask = (1 << (bt + 1)) - 1;

        for (int i = 0; i < n; i++)
            vc.PB(a[i] & mask);

        sort(all(vc));

        sum = 0;

        for (int cr : vc){
            mn = (1 << bt);
            mx = (1 << (bt + 1)) - 1;

            calc(cr);

            if (cr + cr >= mn && cr + cr <= mx)
                sum--;

            mn += (1 << (bt + 1));
            mx = (1 << (bt + 2)) - 2;

            calc(cr);

            if (cr + cr >= mn && cr + cr <= mx)
                sum--;
        }

        sum /= 2;

        if (sum & 1)
            ans += (1 << bt);
    }

    for (int i = 0; i < n; i++)
        ans ^= (a[i] + a[i]);

    cout << ans;

    return 0;
}

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