Submission #686563

#	Time	Username	Problem	Language	Result	Execution time	Memory
686563		opPO	"The Lyuboyn" code (IZhO19_lyuboyn)	C++17	19 / 100	329 ms	116080 KiB

lyuboyn

#pragma GCC optimize("O3,unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define int long long
#define f first
#define s second
#define pb push_back
#define ld long double
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define vec vector

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using oset = tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>;

const ld eps = 1e-6;
const int mod = 1e9 + 7;
const int oo = 2e9;
const ll OO = 2e18;
const int N = 2e5 + 10;

vec<vec<int>> gen(int n)
{
    if (n == 1)
    {
        return {{0}, {1}};
    }
    vec<vec<int>> g = gen(n - 1);
    vec<vec<int>> res;
    for (auto &x : g)
    {
        res.pb({});
        res.back().pb(0);
        for (int &b : x) res.back().pb(b);
    }
    reverse(all(g));
    for (auto &x : g)
    {
        res.pb({});
        res.back().pb(1);
        for (int &b : x) res.back().pb(b);
    }
    return res;
}

int differ(int x, int y)
{
    int res = 0;
    for (int b = 0; b < 20; b++)
    {
        if (((x >> b) & 1) != ((y >> b) & 1)) res++;
    }
    return res;
}

void solve()
{
    int n, k, t, s;
    cin >> n >> k >> t >> s;
    if (k == 1 && s == 0)
    {
        vec<vec<int>> res = gen(n);
        cout << sz(res) << "\n";
        for (auto &x : res)
        {
            for (int &b : x) cout << b;
            cout << "\n";
        }
        return;
    }
    if (k % 2 == 0)
    {
        cout << -1;
        return;
    }
    n = 1 << n;
    vec<vec<bool>> can(1 << n, vec<bool>(n));
    can[1][0] = true;
    vec<vec<int>> from(1 << n, vec<int>(n, -1));
    for (int mask = 0; mask < (1 << n); mask++)
    {
        for (int last = 0; last < n; last++)
        {
            if (((mask >> last) & 1) == 0) continue;
            if (!can[mask][last]) continue;
            for (int to = 0; to < n; to++)
            {
                if ((mask >> to) & 1) continue;
                if (differ(last, to) == k)
                {
                    can[mask | (1 << to)][to] = true;
                    from[mask | (1 << to)][to] = last;
                }
            }
        }
    }
    int mask = (1 << n) - 1, j = -1;
    for (int i = 0; i < n; i++)
    {
        if (can[mask][i] && differ(0, i) == k)
        {
            j = i;
            break;
        }
    }
    vec<int> ans;
    while (mask > 0)
    {
        ans.pb(j);
        int fr = from[mask][j];
        mask ^= (1 << j);
        j = fr;
    }
    reverse(all(ans));
    cout << sz(ans) << "\n";
    for (int &x : ans)
    {
        for (int b = 0; b < 4; b++)
        {
            if ((x >> b) & 1) cout << 1;
            else cout << 0;
        }
        cout << "\n";
    }
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    solve();
    return 0;
}

• Subtask 1: 0 / 0
• Subtask 2: 5 / 5
• Subtask 3: 3 / 3
• Subtask 4: 11 / 11
• Subtask 5: 0 / 15
• Subtask 6: 0 / 18
• Subtask 7: 0 / 31
• Subtask 8: 0 / 17