Submission #1238020

#	Time	Username	Problem	Language	Result	Execution time	Memory
1238020		SamAnd	Closing Time (IOI23_closing)	C++20	8 / 100	97 ms	34112 KiB

closing

#include "closing.h"
#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rnf(2106);
const int N = 200005;

int n;
vector<pair<int, int> > g[N];

void dfs0(int x, int p, vector<ll>& d)
{
    if (x == p)
        d[x] = 0;
    for (int i = 0; i < g[x].size(); ++i)
    {
        int h = g[x][i].fi;
        if (h == p)
            continue;
        d[h] = d[x] + g[x][i].se;
        dfs0(h, x, d);
    }
}

bool dfs1(int x, int p, int y, vector<int>& v)
{
    v.push_back(x);
    if (x == y)
        return true;
    for (int i = 0; i < g[x].size(); ++i)
    {
        int h = g[x][i].fi;
        if (h == p)
            continue;
        if (dfs1(h, x, y, v))
            return true;
    }
    v.pop_back();
    return false;
}

bool c[N];

int max_score(int N, int X, int Y, long long K,
              std::vector<int> U, std::vector<int> V, std::vector<int> W)
{
    n = N;

    for (int i = 0; i <= n + 1; ++i)
    {
        c[i] = false;
        g[i].clear();
    }

    for (int i = 0; i < n - 1; ++i)
    {
        int x = U[i];
        int y = V[i];
        int z = W[i];
        g[x].push_back(m_p(y, z));
        g[y].push_back(m_p(x, z));
    }

    vector<ll> dX(n);
    dfs0(X, X, dX);
    vector<ll> dY(n);
    dfs0(Y, Y, dY);

    vector<int> v;
    dfs1(X, X, Y, v);

    int ans = 0;
    {
    vector<ll> w;
    for (int x = 0; x < n; ++x)
        w.push_back(min(dX[x], dY[x]));
    sort(all(w));
    ll k = K;
    for (int i = 0; i < n; ++i)
    {
        if (k >= w[i])
        {
            k -= w[i];
            ++ans;
        }
    }
    }

    ll k = K;
    int pans = 0;
    vector<ll> w1;
    for (int i = 0; i < sz(v); ++i)
    {
        if (k >= min(dX[v[i]], dY[v[i]]))
        {
            k -= min(dX[v[i]], dY[v[i]]);
            ++pans;
            w1.push_back(max(dX[v[i]], dY[v[i]]) - min(dX[v[i]], dY[v[i]]));
        }
        c[v[i]] = true;
    }
    if (pans != sz(v))
        return ans;

    vector<pair<ll, int> > w;
    for (int x = 0; x < n; ++x)
    {
        if (c[x])
            continue;
        w.push_back(m_p(min(dX[x], dY[x]), x));
    }
    sort(all(w));

    for (int i = -1; i < sz(w); ++i)
    {
        if (i >= 0)
        {
            int x = w[i].se;
            c[x] = true;
            k -= min(dX[x], dY[x]);
            ++pans;
            w1.push_back(max(dX[x], dY[x]) - min(dX[x], dY[x]));
            if (k < 0)
                break;
        }
        vector<ll> w2;
        for (int x = 0; x < n; ++x)
        {
            if (!c[x])
            {
                w2.push_back(max(dX[x], dY[x]));
            }
        }
        sort(all(w2));
        sort(all(w1));

        vector<ll> p1, p2;
        p1.push_back(0);
        for (int i = 0; i < sz(w1); ++i)
        {
            p1.push_back(p1.back() + w1[i]);
        }
        p2.push_back(0);
        for (int i = 0; i < sz(w2); ++i)
        {
            p2.push_back(p2.back() + w2[i]);
        }

        for (int i = 0; i < sz(w1); ++i)
        {
            for (int j = 0; j < sz(w2); ++j)
            {
                if (k >= p1[i] + p2[j])
                    ans = max(ans, pans + i + 2 * j);
            }
        }
    }
    return ans;
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 0 / 9
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 9
• Subtask 6: 0 / 11
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 17