Submission #447418

#	Time	Username	Problem	Language	Result	Execution time	Memory
447418		fuad27	One-Way Streets (CEOI17_oneway)	C++14	30 / 100	12 ms	460 KiB

oneway

#include <bits/stdc++.h>

using namespace std;
#define int long long
vector < int > adj[1002];
pair < int, int > road[1002];
pair < int, int > haveTo[1002];
int subOf[1002];
bool visited[1002];
bool poss = false;
void dfs(int x, int s, int e) {
    visited[x] = true;
    if (x == e) {
        poss = true;
        return;
    }
    subOf[x] = 1;
    for (auto u: adj[x]) {
        if (!visited[u] && (x != s || u != e)) {
            dfs(u, s, e);
        }
        if (poss) return;
    }
}
int32_t main() {
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int s, e;
        cin >> s >> e;
        adj[s].push_back(e);
        adj[e].push_back(s);
        road[i] = {
            s,
            e
        };
    }
    int p;
    cin >> p;
    for (int i = 1; i <= p; i++) {
        int s, e;
        cin >> s >> e;
        haveTo[i] = {
            s,
            e
        };
    }
    for (int i = 1; i <= m; i++) {
        int s = road[i].first, e = road[i].second;
        bool toL = true, toR = true;
        fill(visited, visited + 1002, false);
        fill(subOf, subOf + 1002, 0);
        poss = false;
        int cnt = 0;
        for (auto u: adj[s]) {
            if (u == e) cnt++;
        }
        if (cnt > 1) {
            cout << "B";
            continue;
        }
        dfs(s, s, e);
        if (poss) {
            cout << "B";
        } else {
            for (int j = 1; j <= p; j++) {
                if (subOf[haveTo[j].first] == 1 && subOf[haveTo[j].second] == 0) {
                    toL = false;
                }
                if (subOf[haveTo[j].first] == 0 && subOf[haveTo[j].second] == 1) {
                    toR = false;
                }
            }
            if (toL && toR) cout << "B";
            else if (toL) cout << "L";
            else cout << "R";
        }
    }
}

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