Submission #1051057

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051057		ZanP	Closing Time (IOI23_closing)	C++17	9 / 100	1100 ms	2097152 KiB

closing

#include "closing.h"
#include <iostream>
#include <vector>
#include <algorithm>
#define ll long long
using namespace std;

vector<vector<pair<int, int>>> pov;
vector<ll> distX, distY, cost1, cost2, level, type, q0;
vector<pair<ll, int>> q1, q2, q3;

void dfs(int u, int p, ll dist, vector<ll>& distArray)
{
    distArray[u] = dist;
    for (pair<int, int> pr : pov[u]) {
        int v = pr.first;
        ll w = pr.second;
        if (v == p) { continue; }
        dfs(v, u, dist + w, distArray);
    }
}


int max_score(int N, int X, int Y, ll K, vector <int> U, vector <int> V, vector <int> W)
{
    pov.resize(N);
    distX.resize(N,0);
    distY.resize(N,0);
    cost1.resize(N,0);
    cost2.resize(N,0);
    level.resize(N, 0);
    type.resize(N, 0);
    q0.resize(N);
    q1.reserve(2 * N);
    q2.reserve(N);
    q3.reserve(N);
    for (int j = 0; j < N - 1; j++)
    {
        pov[U[j]].push_back({ V[j], W[j] });
        pov[V[j]].push_back({ U[j], W[j] });
    }
    dfs(X, X, 0, distX);
    dfs(Y, Y, 0, distY);
    for (int i = 0; i < N; i++)
    {
        cost1[i] = min(distX[i], distY[i]);
        cost2[i] = max(distX[i], distY[i]) - cost1[i];
    }
    // case 1:
    for (int i = 0; i < N; i++) q0[i] = -cost1[i];
    sort(q0.begin(), q0.end());
    ll budget = K;
    int ans1 = 0;
    while (q0.size() > 0)
    {
        if (q0.back() + budget >= 0)
        {
            budget += q0.back();
            q0.pop_back();
            ans1++;
        }
        else break;
    }

    // case 2:
    budget = K;
    int ans2 = 0;

    for (int i = 0; i < N; i++) {
        if (distX[i] + distY[i] == distY[X]) {
            type[i] = 0;
            budget -= cost1[i];
            if (budget < 0) { return ans1; }
            level[i] = 1;
            q1.push_back({ -(cost2[i]), i });
            ans2++;
        }
        else if (cost1[i] >= cost2[i]) { //MAYBE >=
            type[i] = 1;
            q2.push_back({ -(cost1[i] + cost2[i]), i });
            q3.push_back({ -cost1[i], i });
        }
        else {
            type[i] = 2;
            q1.push_back({ -(cost1[i]), i });
            q1.push_back({ -(cost2[i]), i });
        }
    }
    if(q1.size())sort(q1.begin(), q1.end());
    if(q2.size())sort(q2.begin(), q2.end());
    if(q3.size())sort(q3.begin(), q3.end());
    while (!q2.empty()) {
        if (q2.back().first + budget < 0) { break; }

        if (q1.size() >= 2) {
            if (-q2.back().first <= -(q1.back().first + q1[q1.size() - 2].first)) {
                budget += q2.back().first;
                level[q2.back().second] = 2;
                q2.pop_back();
                ans2 += 2;
                continue;
            }

            budget += q1.back().first;
            level[q1.back().second]++;
            q1.pop_back();
            ans2 += 1;
            continue;
        }

        budget += q2.back().first;
        level[q2.back().second] = 2;
        q2.pop_back();
        ans2 += 2;
        continue;
    }

    while (!q1.empty()) {
        if (q1.back().first + budget < 0) { break; }
        budget += q1.back().first;
        level[q1.back().second]++;
        q1.pop_back();
        ans2 += 1;
    }

    while (!q3.empty()) {
        if (q3.back().first + budget < 0) { break; }
        if (level[q3.back().second] != 0) {
            q3.pop_back();
            continue;
        }
        budget += q3.back().first;
        level[q3.back().second]++;
        q3.pop_back();
        ans2 += 1;
    }

    return max(ans1, ans2);
}

// int main() {
//     cout << max_score(7, 0, 2, 10, { 0, 0, 1, 2, 2, 5 }, { 1, 3, 2, 4, 5, 6 }, { 2, 3, 4, 2, 5, 3 });
//     return 0;
// }

• Subtask 0: 0 / 0
• Subtask 1: 0 / 8
• Subtask 2: 9 / 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