Submission #492022

#	Time	Username	Problem	Language	Result	Execution time	Memory
492022		davi_bart	Friend (IOI14_friend)	C++14	16 / 100	6 ms	7500 KiB

friend

#include "friend.h"
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
// #define int ll
#define fi first
#define se second
#define ld long double
#define pb push_back
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// Find out best sample
set<int> v[100010];
vector<bool> vis(100010, 0);
vector<int> figli[100010];
void dfs(int pos, int par) {
    if (vis[pos]) return;
    vis[pos] = 1;
    if (par != -1) figli[par].pb(pos);
    for (int x : v[pos]) dfs(x, pos);
}
int memo[100010];

int sol(int pos) {
    if (vis[pos] && pos != 100005) return memo[pos];
    vis[pos] = 1;
    int ans = 0;
    for (int x : figli[pos]) {
        for (int y : figli[x]) {
            int k = sol(y);
            int o = 0;
            for (int z : figli[y]) {
                int u = 0;
                if (v[pos].count(z) == 0) {
                    u = sol(z);
                } else {
                    int l = 0;
                    for (int w : figli[z]) {
                        l += sol(w);
                    }
                    u = max(u, l);
                }
                o += u;
            }
            ans += max(k, o);
        }
    }
    return memo[pos] = ans + 1;
}

void visita(int pos) {
    vis[pos] = 1;
    for (int x : figli[pos]) visita(x);
}
int findSample(int N, int confidence[], int host[], int protocol[]) {
    int a[3] = {0, 0, 0};
    for (int i = 1; i < N; i++) {
        a[protocol[i]]++;
    }
    if (a[1] == N - 1) {
        int tot = 0;
        for (int i = 0; i < N; i++) tot += confidence[i];
        return tot;
    }
    if (a[2] == N - 1) {
        int tot = 0;
        for (int i = 0; i < N; i++) tot = max(confidence[i], tot);
        return tot;
    }

    for (int i = 1; i < N; i++) {
        if (protocol[i] == 0 || protocol[i] == 2) {
            v[host[i]].insert(i);
            v[i].insert(host[i]);
        }
        if (protocol[i] == 1 || protocol[i] == 2) {
            for (int x : v[host[i]]) {
                v[x].insert(i);
                v[i].insert(x);
            }
        }
    }
    int ans = 0;
    for (int i = 0; i < N; i++) {
        if (!vis[i]) {
            dfs(i, -1);
        }
    }
    // cout << "figli 0: ";
    // for (int u : figli[0]) cout << u << " ";
    // cout << endl;
    fill(vis.begin(), vis.end(), 0);
    for (int i = 0; i < N; i++) {
        if (!vis[i]) {
            int ma = 0;
            // for (int a : figli[i]) {
            //     ma = max(ma, sol(a));

            //     for (int b : figli[a]) {
            //         ma = max(ma, sol(b));

            //         for (int c : figli[b]) {
            //             ma = max(ma, sol(c));
            //         }
            //     }
            // }
            ma = max(ma, sol(i));
            figli[100005].clear();
            figli[100005].pb(i);
            ma = max(ma, sol(100005) - 1);
            visita(i);
            // cout << i << " " << ma << endl;
            ans += ma;
        }
    }
    return ans;
}

• Subtask 1: 0 / 11
• Subtask 2: 8 / 8
• Subtask 3: 8 / 8
• Subtask 4: 0 / 19
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31