Submission #1060370

#	Time	Username	Problem	Language	Result	Execution time	Memory
1060370		Zicrus	Toy Train (IOI17_train)	C++17	0 / 100	17 ms	4700 KiB

train

#include <bits/stdc++.h>
#include "train.h"
using namespace std;

typedef long long ll;

vector<unordered_set<ll>> adj, revAdj;
vector<bool> vst;
bool poss = false;
vector<int> a;

void dfs1(ll cur, ll root) {
    vst[cur] = true;
    for (auto &e : revAdj[cur]) {
        if (e == root) poss = true;
        if (vst[e]) continue;
        dfs1(e, root);
    }
}

void dfs2(ll cur, ll par, bool can) {
    vst[cur] = true;
    if (cur == par) {
        for (auto &e : revAdj[cur]) {
            if (vst[e]) continue;
            dfs2(e, cur, true);
        }
        return;
    }

    if (a[cur] != can) {
        if (adj[cur].size() > 1) {
            adj[cur].erase(par);
            for (auto &e : revAdj[cur]) {
                if (vst[e]) continue;
                dfs2(e, cur, !can);
            }
        }
        else {
            for (auto &e : revAdj[cur]) {
                if (vst[e]) continue;
                dfs2(e, cur, can);
            }
        }
    }
    else {
        adj[cur].clear();
        adj[cur].insert(par);
        for (auto &e : revAdj[cur]) {
            if (vst[e]) continue;
            dfs2(e, cur, can);
        }
    }
}

vector<int> who_wins(vector<int> a1, vector<int> r, vector<int> u, vector<int> v) {
    a = a1;
    ll n = a.size(), m = u.size();
	vector<int> res(n);
	adj = vector<unordered_set<ll>>(n);
	revAdj = vector<unordered_set<ll>>(n);
    for (int i = 0; i < m; i++) {
        adj[u[i]].insert(v[i]);
        revAdj[v[i]].insert(u[i]);
    }

    ll charge = 0;
    for (int i = 0; i < n; i++) {
        if (r[i]) {
            charge = i;
            break;
        }
    }

    vst = vector<bool>(n);
    dfs2(charge, charge, true);
	revAdj = vector<unordered_set<ll>>(n);
    for (int i = 0; i < n; i++) {
        for (auto &e : adj[i]) {
            revAdj[e].insert(i);
        }
    }
    vst = vector<bool>(n);
    poss = false;
    dfs1(charge, charge);
    vector<bool> vst2 = vst;
    if (poss) {
        for (int j = 0; j < n; j++) {
            if (!vst2[j]) continue;
            res[j] = true;
        }
    }

	return res;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 11
• Subtask 4: 0 / 11
• Subtask 5: 0 / 12
• Subtask 6: 0 / 51