Submission #636788

#	Time	Username	Problem	Language	Result	Execution time	Memory
636788		tvladm2009	XOR Sum (info1cup17_xorsum)	C++14	0 / 100	1687 ms	20500 KiB

xorsum

#include <iostream>
#include <algorithm>
#define int long long

using namespace std;

const int MAX_N = 1e6;
int a[MAX_N + 1], v[MAX_N + 1];
int n, answer = 0;

int cb(int value) {
    int l = 1, r = n, sol = n + 1;
    while (l < r) {
        int mid = (l + r) / 2;
        if (v[mid] < value) {
            sol = mid;
            l = mid + 1;
        } else {
            r = mid - 1;
        }
    }
    return sol;
}

void solve(int bit) {
    for (int i = 1; i <= n; i++) {
        v[i] = a[i] % (1LL << (bit + 1));
    }
    sort(v + 1, v + n + 1);
    for (int i = 1; i <= n; i++) {
        int p1 = cb(1LL << bit);
        int p2 = cb(1LL << (bit + 1));
        int p3 = cb(1LL << (bit + 2));
        int p4 = cb(1LL << (bit + 3));
        if ((p2 - p1 + n + 1 - p3) & 1) {
            answer += (1LL << bit);
        }
    }
}

signed main() {
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    for (int b = 0; b < 30; b++) {
        solve(b);
    }
    cout << answer;
    return 0;
}

Compilation message (stderr)

xorsum.cpp: In function 'void solve(long long int)':
xorsum.cpp:34:13: warning: unused variable 'p4' [-Wunused-variable]
   34 |         int p4 = cb(1LL << (bit + 3));
      |             ^~

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