Submission #1215895

#	Time	Username	Problem	Language	Result	Execution time	Memory
1215895		vanea	Closing Time (IOI23_closing)	C++20	8 / 100	77 ms	30276 KiB

closing

#include <bits/stdc++.h>
#include "closing.h"
using namespace std;
using ll = long long;

const int mxN = 2e5+10;

array<ll, 2> d[mxN];
vector<array<ll, 2>> adj[mxN];
bitset<mxN> assigned;
array<bool, 2> vis[mxN];
ll val[mxN];

void dfs(int node, int p, int flag) {
    for(auto [it, dist] : adj[node]) {
        if(it == p) continue;
        d[it][flag] = d[node][flag]+dist;
        dfs(it, node, flag);
    }
}

int max_score(int N, int X, int Y, ll K, vector<int> U, vector<int> V, vector<int> W) {
    ll ans = 0, n = N;
    for(int i = 0; i < n-1; i++) {
        adj[U[i]].push_back({V[i], W[i]});
        adj[V[i]].push_back({U[i], W[i]});
    }
    d[X][0] = 0; dfs(X, -1, 0);
    d[Y][1] = 0; dfs(Y, -1, 1);
    set<array<ll, 5>> s;
    s.insert({0, 0, X, 0, 1}); s.insert({0, 0, Y, 1, 1});
    for(auto [it, dist] : adj[X]) {
        s.insert({dist, 0, it, 0, 1});
        vis[it][0] = true;
    }
    vis[X][0] = true; vis[Y][1] = true;
    for(auto [it, dist] : adj[Y]) {
        vis[it][1] = true;
        if(vis[it][0]) {
            ll dist1 = d[it][0], dist2 = d[it][1];
            if(dist1 > dist2) swap(dist2, dist1);
            dist1 *= 2;
            if(dist1 > dist2) {
                s.erase({d[it][0], 0, it, 0, 1});
                s.insert({dist2/2, dist2&1, it, 1, 2});
                continue;
            }

        }
        s.insert({dist, 0, it, 1, 1});
    }
    while(K > 0 && !s.empty()) {
        array<ll, 5> curr = *(s.begin());
        ll dist = curr[0], odd = curr[1], u = curr[2], flag = curr[3], cnt = curr[4];
        dist *= cnt; dist += odd;
        if(K < dist) {
            s.erase(s.begin());
            continue;
        }
        K -= dist;
        ans += cnt;
        s.erase(s.begin());
        if(!assigned[u] && cnt == 1) {
            assigned[u] = true;
            val[u] = dist;
            auto it = s.lower_bound({d[u][1-flag], 0, u, 1-flag, 1});
            if(it != s.end() && (*it)[2] == u) {
                array<ll, 5> now = {(*it)[0]-dist, 0, u, 1-flag, 1};
                s.erase(it);
                s.insert(now);
            }
        }
        for(auto [it, _] : adj[u]) {
            if(!vis[it][flag]) {
                vis[it][flag] = true;
                if(assigned[it]) {
                    s.insert({d[it][flag]-val[it], it, flag});
                }
                else if(vis[it][1-flag]) {
                    ll dist1 = d[it][1-flag], dist2 = d[it][flag];
                    if(dist1 > dist2) swap(dist2, dist1);
                    dist1 *= 2;
                    if(dist1 > dist2) {
                        s.erase({d[it][1-flag], 0, it, 1-flag, 1});
                        s.insert({dist2/2, dist2&1, it, flag, 2});
                    }
                    else {
                        s.insert({d[it][flag], 0, it, flag, 1});
                    }
                }
                else {
                    s.insert({d[it][flag], 0, it, flag, 1});
                }
            }
            if(cnt == 2) {
                flag = 1-flag;
                if(!vis[it][flag]) {
                    vis[it][flag] = true;
                    if(assigned[it]) {
                        s.insert({d[it][flag]-val[it], it, flag});
                    }
                    else if(vis[it][1-flag]) {
                        ll dist1 = d[it][1-flag], dist2 = d[it][flag];
                        if(dist1 > dist2) swap(dist2, dist1);
                        dist1 *= 2;
                        if(dist1 > dist2) {
                            s.erase({d[it][1-flag], 0, it, 1-flag, 1});
                            s.insert({dist2/2, dist2&1, it, 1, 2});
                        }
                        else {
                            s.insert({d[it][flag], 0, it, flag, 1});
                        }
                    }
                    else {
                        s.insert({d[it][flag], 0, it, flag, 1});
                    }
                }
            }
        }
    }
    for(int i = 0; i < n; i++) {
        adj[i].clear();
        assigned[i] = false;
        val[i] = 0; vis[i][0] = 0; vis[i][1] = 0;
        d[i][0] = 0; d[i][1] = 0;
    }
    return ans;
}

/*int main()
{
    vector<int> a = {0, 0, 1, 2, 2, 5}, b = {1, 3, 2, 4, 5, 6}, c = {2, 3, 4, 2, 5, 3};
    cout << max_score(7, 0, 2, 10, a, b, c) << ' ';
    vector<int> d = {0, 1, 2}, e = {1, 2, 3}, f = {18, 1, 19};
    cout << max_score(4, 0, 3, 20, d, e, f);
}*/

• 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