Submission #952486

#	Time	Username	Problem	Language	Result	Execution time	Memory
952486		_callmelucian	One-Way Streets (CEOI17_oneway)	C++14	0 / 100	2024 ms	2792 KiB

oneway

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

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const int mn = 1e5 + 5;
vector<int> adj[mn];
bool vis[mn];

void dfs (int u) {
    if (vis[u]) return;
    vis[u] = 1;
    for (int v : adj[u]) dfs(v);
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n, m; cin >> n >> m;
    vector<int> ans(m); // 0: none, 1: left, 2: right, 3: both
    vector<pii> edge(m);

    for (int i = 0; i < m; i++) {
        int a, b; cin >> a >> b;
        edge[i] = {a, b};
    }

    int p; cin >> p;
    vector<pii> cond(p);

    for (int i = 0; i < p; i++) {
        int a, b; cin >> a >> b;
        cond[i] = {a, b};
    }

    for (int mask = 0; mask < (1 << m); mask++) {
        for (int i = 1; i <= n; i++) adj[i].clear();
        for (int i = 0; i < m; i++) {
            int a, b; tie(a, b) = edge[i];

            if (mask & (1 << i)) adj[a].push_back(b); // right
            else adj[b].push_back(a); // left
        }

        bool flg = 1;
        for (pii it : cond) {
            for (int i = 1; i <= n; i++) vis[i] = 0;
            dfs(it.first);
            if (!vis[it.second]) flg = 0;
        }

        if (flg) {
            for (int i = 0; i < m; i++) {
                if (mask & (1 << i)) {
                    if (ans[i] == 0 || ans[i] == 2) ans[i] = 2;
                    else if (ans[i] == 1) ans[i] = 3;
                }
                else {
                    if (ans[i] == 0 || ans[i] == 1) ans[i] = 1;
                    else if (ans[i] == 2) ans[i] = 3;
                }
            }
        }
    }

    for (int i = 0; i < m; i++) {
        if (ans[i] == 1) cout << 'L';
        else if (ans[i] == 2) cout << 'R';
        else cout << 'B';
    }

    return 0;
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40