Submission #1264879

#	Time	Username	Problem	Language	Result	Execution time	Memory
1264879		BlockOG	Dreaming (IOI13_dreaming)	C++20	32 / 100	40 ms	13892 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>

// mrrrow meeow :3
// go play vivid/stasis now! it's free on steam

#define fo(i, a, b) for (auto i = (a); i < (b); i++)
#define of(i, a, b) for (auto i = (b); i-- > (a);)
#define f first
#define s second
#define pb push_back
#define pob pop_back
#define lb lower_bound
#define ub upper_bound
#define be(a) a.begin(), a.end()
using namespace std;

int ____init = [] {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    return 0;
}();

struct Component {
    int diameter;
    int longest;
};

bool vis[100000];
vector<pair<int, int>> adj[100000];

pair<int, int> dfs1(int i, int p = -1, int d = 0) {
    vis[i] = true;

    pair<int, int> res = {d, i};
    for (auto [j, t] : adj[i]) {
        if (j == p) continue;
        res = max(res, dfs1(j, i, d + t));
    }

    return res;
}

Component dfs2(int i, int p = -1, int d = 0) {
    Component res;
    res.diameter = d;
    res.longest = 2000000000;
    for (auto [j, t] : adj[i]) {
        if (j == p) continue;
        Component dres = dfs2(j, i, d + t);
        res.diameter = max(res.diameter, dres.diameter);
        res.longest = min(res.longest, dres.longest);
    }

    res.longest = min(res.longest, max(d, res.diameter - d));
    return res;
}

int travelTime(int n, int m, int l, int a[], int b[], int t[]) {
    fo(i, 0, m) {
        adj[a[i]].pb({b[i], t[i]});
        adj[b[i]].pb({a[i], t[i]});
    }

    vector<Component> comps;
    fo(i, 0, n) if (!vis[i]) {
        comps.pb(dfs2(dfs1(i).s));
    }

    sort(be(comps), [](Component &a, Component &b) { return a.longest < b.longest; });

    Component res = comps.back();
    comps.pop_back();

    for (Component i : comps) {
        res.diameter = max(max(res.diameter, i.diameter), res.longest + l + i.longest);
        res.longest = max(res.longest, i.longest + l);
    }

    return res.diameter;
}

• Subtask 1: 14 / 14
• Subtask 2: 0 / 10
• Subtask 3: 0 / 23
• Subtask 4: 18 / 18
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23