Submission #1200840

#	Time	Username	Problem	Language	Result	Execution time	Memory
1200840		Nelt	Machine (IOI24_machine)	C++20	10 / 100	3 ms	444 KiB

machine

#include "machine.h"
#include <bits/stdc++.h>
#define ll long long
#define endl "\n"
using namespace std;

std::vector<int> find_permutation(int n)
{
    std::vector<int> a(n);
    for (ll i = 0; i < n; i++)
        a[i] = i;
    if (n & 1)
    {
        std::vector<int> b = use_machine(a);
        ll xxor = 0;
        for (ll i = 0; i < n; i++) xxor ^= i ^ b[i];
        for (ll i = 0; i < n; i++) b[i] ^= xxor;
        return b;
    }
    else if ((1 << __lg(n)) == n)
    {
        a[n - 1] = n;
        vector<int> b = use_machine(a);
        ll cnt = 0;
        for (ll i = 0; i < n; i++) cnt += (b[i] & n) > 0;
        if (cnt > 1)
            for (ll i = 0; i < n; i++) b[i] ^= n;
        ll x = 0;
        for (ll i = 0; i < n; i++) if ((b[i] & n) > 0)
            x = b[i] ^ n;
        for (ll i = 0; i < n; i++)
        {
            b[i] ^= x;
            if (b[i] == n) b[i]--;
        }
        return b;
    }
    else
    {
        vector<int> b = use_machine(a), c;
        for (ll x = 0; x < 256; x++)
        {
            c = b;
            for (ll i = 0; i < n; i++) c[i] ^= x;
            sort(c.begin(), c.end());
            if (c == a)
            {
                for (ll i = 0; i < n; i++) b[i] ^= x;
                return b;
            }
        }
    }
    return {0};
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 7
• Subtask 2: 0 / 12
• Subtask 3: 0 / 19
• Subtask 4: 0 / 21
• Subtask 5: 10 / 10
• Subtask 6: 0 / 31