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Submission #320476

# Submission time Handle Problem Language Result Execution time Memory
320476 2020-11-08T20:25:43 Z qpwoeirut XOR Sum (info1cup17_xorsum) C++17
18 / 100
 125 ms 22884 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int MN = 1001001;
const int MX = 4001;
const int BITS = 60;

ll N;
ll A[MN], freq[MN];
ll ct[BITS];
int main() {
    cin.tie(0)->sync_with_stdio(0);

    cin >> N;
    for (int i=0; i<N; ++i) {
        cin >> A[i];
    }

    ll ans = 0;
    if (N <= MX) {
        for (int i=0; i<N; ++i) {
            for (int j=i; j<N; ++j) {
                ll x = A[i] + A[j];
                ans ^= x;
            }
        }
    } else {
        for (int i=0; i<N; ++i) ++freq[A[i]];
        for (int i=0; i<MX; ++i) {
            for (int j=i; j<MX; ++j) {
                ll x;
                if (i == j) {
                    x = (freq[i] * (freq[i] + 1)) >> 1;
                } else {
                    x = freq[i] * freq[j];
                }
                if (x & 1) ans ^= (i+j);
                //if (x) cerr << i << ' ' << j << ' ' << x << endl;
            }
        }
    }

    cout << ans << endl;
}

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 364 KB Output is correct
2 Correct 6 ms 364 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 119 ms 12772 KB Output is correct
2 Correct 99 ms 12004 KB Output is correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 119 ms 12772 KB Output is correct
2 Correct 99 ms 12004 KB Output is correct
3 Incorrect 125 ms 22884 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #4
0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 364 KB Output is correct
2 Correct 6 ms 364 KB Output is correct
3 Runtime error 15 ms 3112 KB Execution killed with signal 11 (could be triggered by violating memory limits)
4 Halted 0 ms 0 KB -

Subtask #5
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 364 KB Output is correct
2 Correct 6 ms 364 KB Output is correct
3 Correct 119 ms 12772 KB Output is correct
4 Correct 99 ms 12004 KB Output is correct
5 Incorrect 125 ms 22884 KB Output isn't correct
6 Halted 0 ms 0 KB -