Submission #699198

#	Time	Username	Problem	Language	Result	Execution time	Memory
699198		abysmal	XOR Sum (info1cup17_xorsum)	C++14	100 / 100	554 ms	17496 KiB

xorsum

#include<iostream>
#include<stdio.h>
#include<stdint.h>
#include<vector>
#include<algorithm>
#include<utility>
#include<set>
#include<map>
#include<queue>
#include<stack>
#include<deque>
#include<string>
#include<assert.h>
#include<math.h>
#include<chrono>
#include<random>
#include<bitset>

using namespace std;

const int64_t INF = (int64_t) 1e9 + 5;
const int64_t mINF = (int64_t) 2 * 1e6 + 5;
const int64_t MOD = (int64_t) 1e9 + 19972207;
const int nbit = 30;
const int ndig = 10;
const int nchar = 26;
const int p1 = 31;
const int p2 = 53;
const int D = 4;
int dr[D] = {0, 1, 0, -1};
int dc[D] = {1, 0, -1, 0};
// 0 right // 1 down // 2 left // 3 up

struct Solution
{
    int n;
    vector<int> a;
    Solution() {}

    void solve()
    {
        cin >> n;
        a.resize(n);
        for(int i = 0; i < n; i++)
        {
            cin >> a[i];
        }

        int ans = 0;
        sort(a.begin(), a.end());
        for(int b = nbit; b >= 0; b--)
        {
            Sort(b);

            int j = n;
            int k = n;
            int l = n;

            int cnt = 0;
            for(int i = 0; i < n; i++)
            {
                j = max(j, i);
                k = max(k, i);
                l = max(l, i);

                while(i < j && a[i] + a[j - 1] >= MASK(b)) j--;
                while(i < k && a[i] + a[k - 1] > MASK(b + 1) - 1) k--;
                while(i < l && a[i] + a[l - 1] >= MASK(b + 1) + MASK(b)) l--;

                cnt += k - j;
                cnt += n - l;
            }

            if(cnt % 2 != 0) ans |= MASK(b);
        }

        cout << ans << "\n";
    }

    void Sort(int b)
    {
        vector<int> tmp = a;
        int x = n;
        for(int i = 0; i < n; i++)
        {
            if(tmp[i] >= MASK(b + 1))
            {
                tmp[i] %= MASK(b + 1);
                x = min(x, i);
            }
        }

        int id = 0;
        int l = 0;
        int r = x;
        while(l < x && r < n)
        {
            if(tmp[l] < tmp[r]) a[id] = tmp[l++];
            else a[id] = tmp[r++];

            id++;
        }

        while(l < x)
        {
            a[id] = tmp[l++];
            id++;
        }

        while(r < n)
        {
            a[id] = tmp[r++];
            id++;
        }
    }

    int modsub(int t1, int t2)
    {
        int64_t res = t1 - t2;
        if(res < 0) res += MOD;

        return res;
    }

    int modadd(int t1, int t2)
    {
        int64_t res = t1 + t2;
        if(res >= MOD) res -= MOD;

        return res;
    }

    int modmul(int t1, int t2)
    {
        int64_t res = 1LL * t1 * t2;
        return (res % MOD);
    }

    bool BIT(int mask, int j)
    {
        return (mask & MASK(j));
    }

    int MASK(int j)
    {
        return (1 << j);
    }

    int64_t Abs(int64_t t1)
    {
        if(t1 < 0) return -t1;
        return t1;
    }
};

void __startup()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);

//    freopen("in.txt", "r", stdin);
//    freopen("out.txt", "w", stdout);
}

int main()
{
    __startup();
    int t = 1;
//    cin >> t;

    for(int i = 1; i <= t; i++)
    {
        Solution().solve();
    }

    return 0;
}

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