제출 #1170754

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1170754		anmattroi	봉쇄 시간 (IOI23_closing)	C++17	8 / 100	128 ms	40280 KiB

closing

#include "closing.h"
#include <bits/stdc++.h>
#define maxn 200005
#define fi first
#define se second
using namespace std;
using ii = pair<int, int>;

int n, x, y; int64_t k;

int64_t disX[maxn], disY[maxn];

int64_t cost_level_one[maxn], cost_level_two[maxn];

vector<ii> adj[maxn];

void calcdisX() {

    function<void(int, int)> dfs = [&](int u, int dad) {
        for (auto [v, l] : adj[u])
        if (v != dad) {
            disX[v] = disX[u] + l;
            dfs(v, u);
        }
    };

    disX[x] = 0;
    dfs(x, -1);
}

void calcdisY() {

    function<void(int, int)> dfs = [&](int u, int dad) {
        for (auto [v, l] : adj[u])
        if (v != dad) {
            disY[v] = disY[u] + l;
            dfs(v, u);
        }
    };

    disY[y] = 0;
    dfs(y, -1);
}


int sub1() {
    vector<int64_t> nho;
    for (int i = 0; i < n; i++) nho.emplace_back(min(disX[i], disY[i]));
    sort(nho.begin(), nho.end());

    int64_t ans = 0;
    for (int i = 0; i < n; i++) {
        ans += nho[i];
        if (ans > k) return i;
    }
    return n;
}


int sub2() {
    int ans = 0;
    for (int i = 0; i < n; i++) {
        cost_level_one[i] = min(disX[i], disY[i]);
        cost_level_two[i] = max(disX[i], disY[i]) - cost_level_one[i];
    }

    int64_t sum = 0;
    vector<int> type(n, 0);

    priority_queue<ii, vector<ii>, greater<ii> > q;

    for (int i = 0; i < n; i++)
        if (disX[i] + disY[i] == disX[y]) {
            type[i] = 1;
            ++ans;
            sum += cost_level_one[i];
            q.push(ii{cost_level_two[i], i});
        } else {
            if (cost_level_one[i] > cost_level_two[i]) {
                q.push(ii{cost_level_one[i] + cost_level_two[i], i});
                type[i] = 2;
            } else {
                type[i] = 1;
                q.push(ii{cost_level_one[i], i});
            }
        }
    if (sum > k) return 0;

    while (!q.empty()) {
        if (sum + q.top().fi > k) break;
        sum += q.top().fi; ++ans;
        int u = q.top().se; q.pop();
        if (type[u] == 2) {
            type[u] = 3;
            continue;
        }
        if (type[u] == 1) {
            q.push(ii{cost_level_two[u], u});
            type[u] = 2;
        }

    }
    for (int i = 0; i < n; i++)
    if (disX[i] + disY[i] != disX[y] && cost_level_one[i] > cost_level_two[i] && sum + cost_level_one[i] <= k && type[i] == 2) {
        sum += cost_level_one[i];
        ++ans;
    }
    return ans;
}

int max_score(int N, int X, int Y, long long K, vector<int> U, vector<int> V, vector<int> W) {
    n = N; x = X; y = Y; k = K;
    for (int i = 0; i < N-1; i++) {
        adj[U[i]].emplace_back(V[i], W[i]);
        adj[V[i]].emplace_back(U[i], W[i]);
    }
    calcdisX(); calcdisY();
    int ans = max(sub1(), sub2());
    for (int i = 0; i < N; i++) adj[i].clear();
    return ans;
}
/*
2
7 0 2 10
0 1 2
0 3 3
1 2 4
2 4 2
2 5 5
5 6 3
4 0 3 20
0 1 18
1 2 1
2 3 19
*/
/*
1
4 0 3 20
0 1 18
1 2 1
2 3 19
*/
//6 3

• 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