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Submission #743725

# Submission time Handle Problem Language Result Execution time Memory
743725 2023-05-17T19:06:34 Z borisAngelov Xor Sort (eJOI20_xorsort) C++17
100 / 100
 8 ms 1028 KB 
#include <iostream>
#include <vector>

using namespace std;

const int maxn = 1005;

int n, s;

int a[maxn];

void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main()
{
    fastIO();

    cin >> n >> s;

    for (int i = 1; i <= n; ++i)
    {
        cin >> a[i];
    }

    vector<pair<int, int>> ans;

    if (s == 1)
    {
        int last = 0;

        for (int i = n; i > 1; --i)
        {
            int idx = 1;

            for (int j = 1; j <= i; ++j)
            {
                if ((a[j] ^ last) > (a[idx] ^ last))
                {
                    idx = j;
                }
            }

            for (int j = 1; j <= i; ++j)
            {
                if (j != n)
                {
                    ans.push_back(make_pair(j, j + 1));
                    a[j] = (a[j] ^ a[j + 1]);
                }
            }

            for (int j = idx + 1; j <= i; ++j)
            {
                ans.push_back(make_pair(j, j - 1));
                a[j] = (a[j] ^ a[j - 1]);
            }

            for (int j = idx - 1; j > 1; --j)
            {
                ans.push_back(make_pair(j - 1, j));
                a[j - 1] = (a[j - 1] ^ a[j]);
            }

            /*for (int j = 1; j <= n; ++j)
            {
                cout << a[j] << ' ';
            }

            cout << endl;*/

            last = a[i];
        }

        ans.push_back(make_pair(1, 2));

        a[1] = (a[1] ^ a[2]);
    }
    else
    {
        for (int bit = 19; bit >= 0; --bit)
        {
            for (int i = 1; i < n; ++i)
            {
                if (((a[i] & (1 << bit)) != 0) && ((a[i + 1] & (1 << bit)) == 0))
                {
                    a[i + 1] = (a[i] ^ a[i + 1]);
                    ans.push_back(make_pair(i + 1, i));
                }

                if (((a[i] & (1 << bit)) != 0) && ((a[i + 1] ^ a[i]) < a[i]))
                {
                    a[i] = (a[i] ^ a[i + 1]);
                    ans.push_back(make_pair(i, i + 1));
                }
            }
        }
    }

    /*for (int i = 1; i <= n; ++i)
    {
        cout << a[i] << ' ';
    }

    cout << endl;*/

    cout << ans.size() << endl;

    for (auto [x, y] : ans)
    {
        cout << x << ' ' << y << "\n";
    }

    return 0;
}

Subtask #1
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 4 ms 728 KB Output is correct
5 Correct 4 ms 728 KB Output is correct
6 Correct 4 ms 728 KB Output is correct
7 Correct 4 ms 728 KB Output is correct
8 Correct 4 ms 728 KB Output is correct
9 Correct 4 ms 728 KB Output is correct
10 Correct 4 ms 728 KB Output is correct
11 Correct 4 ms 728 KB Output is correct
12 Correct 4 ms 732 KB Output is correct
13 Correct 4 ms 728 KB Output is correct
14 Correct 4 ms 728 KB Output is correct
15 Correct 4 ms 748 KB Output is correct

Subtask #2
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 4 ms 728 KB Output is correct
5 Correct 4 ms 728 KB Output is correct
6 Correct 4 ms 728 KB Output is correct
7 Correct 4 ms 728 KB Output is correct
8 Correct 4 ms 728 KB Output is correct
9 Correct 4 ms 728 KB Output is correct
10 Correct 4 ms 728 KB Output is correct
11 Correct 4 ms 728 KB Output is correct
12 Correct 4 ms 732 KB Output is correct
13 Correct 4 ms 728 KB Output is correct
14 Correct 4 ms 728 KB Output is correct
15 Correct 4 ms 748 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 4 ms 728 KB Output is correct
18 Correct 6 ms 980 KB Output is correct
19 Correct 6 ms 984 KB Output is correct
20 Correct 7 ms 980 KB Output is correct
21 Correct 6 ms 984 KB Output is correct
22 Correct 7 ms 984 KB Output is correct
23 Correct 6 ms 980 KB Output is correct
24 Correct 6 ms 980 KB Output is correct
25 Correct 6 ms 980 KB Output is correct
26 Correct 7 ms 980 KB Output is correct
27 Correct 6 ms 1028 KB Output is correct
28 Correct 7 ms 984 KB Output is correct
29 Correct 6 ms 980 KB Output is correct
30 Correct 8 ms 980 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 5 ms 856 KB Output is correct
6 Correct 5 ms 912 KB Output is correct
7 Correct 6 ms 844 KB Output is correct
8 Correct 5 ms 900 KB Output is correct
9 Correct 6 ms 856 KB Output is correct
10 Correct 5 ms 856 KB Output is correct
11 Correct 6 ms 856 KB Output is correct
12 Correct 5 ms 972 KB Output is correct
13 Correct 6 ms 984 KB Output is correct
14 Correct 6 ms 856 KB Output is correct
15 Correct 7 ms 980 KB Output is correct