제출 #1146512

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1146512		feev1x	XOR Sum (info1cup17_xorsum)	C++20	7 / 100	1701 ms	170284 KiB

xorsum

/**
 *    author:  feev1x
 *    created: 06.02.2025 09:49:04
**/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace std;

#define double long double

#define ord tree<double, null_type, less_equal<double>, rb_tree_tag, tree_order_statistics_node_update>


int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int n; std::cin >> n;

    std::vector<int> a(n);
    for (auto &u: a) {
        std::cin >> u;
    }

    std::vector<ord> cho(31);
    std::vector<ord> necho(31);

    int res = 0;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < 31; ++j) {
            bool flag = false;
            double val = fmod((double)a[i] / (double)(1 << j), 1);

            if ((a[i] / (1 << j)) & 1) {
                necho[j].insert(val);

                double inv = 1 - val;

                int it = cho[j].order_of_key(inv);

                bool nw = false;
                if (cho[j].size()) {
                    nw ^= it & 1;
                }

                it = necho[j].order_of_key(inv);

                if (necho[j].size()) {
                    nw ^= (necho[j].size() - it) & 1;
                }

                flag ^= nw;
            } else {
                cho[j].insert(val);

                double inv = 1 - val;

                int it = necho[j].order_of_key(inv);

                bool nw = false;
                if (necho[j].size()) {
                    nw ^= it & 1;
                }

                it = cho[j].order_of_key(inv);

                if (cho[j].size()) {
                    nw ^= (cho[j].size() - it) & 1;
                }

                flag ^= nw;
            }
            
            if (flag) {
                res ^= (1 << j);
            }
        }

    }

    std::cout << res << '\n';
    return 0;
}

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