Submission #1009469

#	Time	Username	Problem	Language	Result	Execution time	Memory
1009469		cpismylifeOwO	XOR Sum (info1cup17_xorsum)	C++17	7 / 100	509 ms	23772 KiB

xorsum

#include <bits/stdc++.h>

using namespace std;

const long long mod = 1e9 + 7;
const int MaxN = 1e6 + 5;
const int MaxLog = 31;

int n;
long long arr[MaxN];

void Inp()
{
    cin >> n;
    for (int x = 1; x <= n; x++)
    {
        cin >> arr[x];
    }
}

long long arr2[MaxN];
int id[2][MaxN];

void Exc()
{
    long long res = 0;
    int k = 1;
    for (int x = 1; x <= n; x++)
    {
        if (arr[x] % 2 == 0)
        {
            id[0][k] = x;
            k++;
        }
        arr2[x] = arr[x] & 1;
    }
    if ((1ll * (k - 1) * (n - k + 1)) & 1)
    {
        res ^= 1ll;
    }
    for (int x = 1; x <= n; x++)
    {
        if (arr[x] & 1ll)
        {
            id[0][k] = x;
            k++;
        }
    }
    bool avl = true;
    for (int x = 1; x < MaxLog; x++)
    {
        k = 1;
        for (int y = 1; y <= n; y++)
        {
            if (!((arr[id[!avl][y]] >> x) & 1))
            {
                id[avl][k] = id[!avl][y];
                k++;
            }
        }
        for (int y = 1; y <= n; y++)
        {
            if ((arr[id[!avl][y]] >> x) & 1)
            {
                id[avl][k] = id[!avl][y];
                k++;
            }
        }
        for (int y = 1; y <= n; y++)
        {
            arr2[y] ^= (arr[y] & (1ll << x));
        }
        long long cnt = n * (n + 1) / 2;
        int z1 = n, z2 = n, z3 = n;
        long long a = (1ll << x) + (1ll << (x + 1)), b = (1ll << (x + 1)), c = (1ll << x);
        for (int y = 1; y <= n; y++)
        {
            z1 = max(z1, y - 1);
            while (z1 >= y && (arr2[id[avl][y]] + arr2[id[avl][z1]] >= a))
            {
                z1--;
            }
            cnt -= z1 - y + 1;
            z2 = max(z2, y - 1);
            while (z2 >= y && (arr2[id[avl][y]] + arr2[id[avl][z2]] >= b))
            {
                z2--;
            }
            cnt += z2 - y + 1;
            z3 = max(z3, y - 1);
            while (z3 >= y && (arr2[id[avl][y]] + arr2[id[avl][z3]] >= c))
            {
                z3--;
            }
            cnt -= z3 - y + 1;
            if (z1 < y && z2 < y && z3 < y)
            {
                break;
            }
        }
        avl = !avl;
        //cout << cnt << " ";
        if (cnt >= 0 && cnt & 1)
        {
            res ^= (1ll << x);
        }
        //cout << cnt << "\n";
    }
    cout << res;
}

int main()
{
    //freopen("B.INP", "r", stdin);
    //freopen("B.OUT", "w", stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int test = 1;
    //cin >> test;
    for (int x = 1; x <= test; x++)
    {
        Inp();
        Exc();
    }
    return 0;
}

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