Submission #1331512

#	Time	Username	Problem	Language	Result	Execution time	Memory
1331512		nicolo_010	Closing Time (IOI23_closing)	C++20	21 / 100	1096 ms	24524 KiB

closing

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

vector<vector<pii>> adj;

void dfs(int u, vector<ll> &dis, int p=-1, ll w=0) {
    dis[u] = w;
    for (auto [v, pe] : adj[u]) {
        if (v==p) continue;
        dfs(v, dis, u, w+pe);
    }
}

int max_score(int n, int x, int y, long long k,
              std::vector<int> U, std::vector<int> V, std::vector<int> W) {
    adj.assign(n, {});
    vector<ll> disX(n, 0);
    vector<ll> disY(n, 0);
    for (int i=0; i<n-1; i++) {
        int u = U[i];
        int v = V[i];
        int w = W[i];
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }
    dfs(x, disX);
    dfs(y, disY);
    //Fijar [l, r] que me expando en X, expandir Y greedily
    int res=0;
    for (int l=0; l<=x; l++) {
        for (int r=n-1; r>=x; r--) {
            ll mx=k;
            vector<bool> vis(n, false);
            for (int i=l; i<=r; i++) {
                vis[i] = true;
                mx -= disX[i];
            }
            //cout << l << " " << r << " " << mx << endl;
            if (mx<0) continue;
            vector<ll> cost(n, 0);
            for (int i=0; i<n; i++) {
                if (vis[i]) {
                    if (disX[i] >= disY[i]) {
                        cost[i] = 0;
                    }
                    else {
                        cost[i] = disY[i]-disX[i];
                    }
                }
                else {
                    cost[i] = disY[i];
                }
            }
            int ans = r-l+1;
            vector<ll> acc;
            if (r>=y) {
                //etsa contenido
                for (int i=0; i<n; i++) {
                    acc.push_back(cost[i]);
                }
                sort(acc.begin(), acc.end());
                ll P = mx;
                for (auto v : acc) {
                    if (v<=P) {
                        P -= v;
                        ans++;
                    }
                }
                res = max(res, ans);
                continue;
            }
            for (int i=r+1; i<n; i++) {
                acc.push_back(disY[i]);
            }
            sort(acc.begin(), acc.end());
            ll P = mx;
            //Caso no solaparlos
            for (auto v : acc) {
                if (v<=P) {
                    P -= v;
                    ans++;
                }
            }
            res = max(res, ans);
            acc.clear();
            for (int i=0; i<=r; i++) {
                acc.push_back(cost[i]);
            }
            for (int i=y+1; i<n; i++) {
                acc.push_back(cost[i]);
            }
            ans = (r-l+1);
            //r+1...y
            //cout << l << " " << r << " " << y << endl;
            ans += (y-(r+1)+1);
            sort(acc.begin(), acc.end());
            P = mx;
            for (int i=r+1; i<=y; i++) {
                P -= disY[i];
            }
            if (P<0) continue;
            for (auto v : acc) {
                if (v<=P) {
                    P -= v;
                    ans++;
                }
            }
            res = max(res, ans);
        }
    }
    return res;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 8
• Subtask 2: 9 / 9
• Subtask 3: 12 / 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