Submission #395641

#	Time	Username	Problem	Language	Result	Execution time	Memory
395641		idk321	Toy Train (IOI17_train)	C++11	16 / 100	70 ms	2932 KiB

train

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

const int N = 5000;
set<int> adj[N];
vector<int> adjIn[N];

vector<int> a;
vector<int> r;
vector<int> u;
vector<int> v;



bool miss[N];


int out[N];
int timer = 0;

bool goodA[N];
bool goodB[N];

vector<int> comps;

vector<int> st;
bool onSt[N];

bool vis[N];
void dfs(int node)
{
    st.push_back(node);
    onSt[node] = true;
    vis[node] = true;

    for (int next : adj[node])
    {
        if (miss[next]) continue;

        if (!vis[next])
        {
            dfs(next);
        } else if (onSt[next])
        {
            int cur = st.size() - 1;
            while (true)
            {
                if (r[st[cur]] == 1) goodA[st[cur]] = true;
                goodB[st[cur]] = true;
                if (st[cur] == node) break;
                cur--;
            }
        }
    }

    onSt[node] = false;
    st.pop_back();
}




bool reachable[N];
void goReach(int node)
{
    reachable[node] = true;
    for (int next : adjIn[node])
    {
        if (reachable[next]) continue;
        goReach(next);
    }
}


std::vector<int> who_wins(std::vector<int> A, std::vector<int> R, std::vector<int> U, std::vector<int> V) {
    a = A;
    r = R;
    u = U;
    v = V;

    int n = a.size();
    int m = u.size();
    bool simple = true;
    for (int i = 0; i < m; i++)
    {
        if (!(v[i] == u[i] || v[i] == u[i] + 1)) simple = false;
        adj[u[i]].insert(v[i]);
        adjIn[v[i]].push_back(u[i]);
    }

    std::vector<int> res(a.size());


    bool allA = true;
    bool allB = true;
    for (int i = 0; i < n; i++)
    {
        if (a[i] == 1) allB = false;
        if (a[i] == 0) allA = false;
    }
    //cout << simple << endl;
    if (simple)
    {
        for (int i = 0; i < n; i++)
        {
            int cur = i;
            bool good = false;
            int travelled = 0;
            while (travelled < n)
            {
                if (a[cur] == 1)
                {
                    if (r[cur] == 1)
                    {
                        if (adj[cur].find(cur) != adj[cur].end())
                        {
                            good = true;
                            break;
                        }
                    }

                    for (int next : adj[cur])
                    {
                        if (next != cur)
                        {
                            cur = next;
                            break;
                        }
                    }
                } else
                {
                    if (r[cur] != 1)
                    {
                        if (adj[cur].find(cur) != adj[cur].end())
                        {
                            break;
                        }
                    }

                    for (int next : adj[cur])
                    {
                        if (next != cur)
                        {
                            cur = next;
                            break;
                        }
                    }
                }

                travelled++;
            }

            if (r[cur]) good = true;
            res[i] = good;
        }

        return res;
    } else if (allA)
    {
        for (int i = 0; i < n; i++)
        {
            if (!vis[i]) dfs(i);
        }

        for (int i = 0; i < n; i++)
        {
            if (goodA[i] && !reachable[i]) goReach(i);
        }
        for (int i = 0; i < n; i++) res[i] = reachable[i];

        return res;
    } else if (allB)
    {
        for (int i = 0; i < n; i++) if (r[i]) miss[i] = true;

        for (int i = 0; i < n; i++)
        {
            if (!miss[i] && !vis[i]) dfs(i);
        }

        for (int i = 0; i < n; i++)
        {
            if (goodB[i] && !reachable[i]) goReach(i);
        }

        for (int i = 0; i < n; i++)
        {
            res[i] = !reachable[i];
        }

        return res;
    }

	return res;
}

/*
10 11
0 0 0 0 0 0 0 0 0 0
0 0 1 0 0 0 1 0 0 0
0 1
1 2
2 1
1 3
1 4
4 5
5 4
6 6
7 7
8 9
9 8
*/

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