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Submission #878735

# Submission time Handle Problem Language Result Execution time Memory
878735 2023-11-25T06:41:55 Z Ghulam_Junaid One-Way Streets (CEOI17_oneway) C++17
60 / 100
 3000 ms 12888 KB 
#include <bits/stdc++.h>
using namespace std;

const int N = 1e5 + 10;
int n, m, p, h[N], mnh[N], st[N], ft[N], tme;

bool vis[N];
vector<pair<int, int>> g[N], edges, important;
string s;

bool in_sub(int u, int v){
    return (st[v] <= st[u] && st[u] < ft[v]);
}

void dfs(int v, int prev = -1){
    vis[v] = 1;
    mnh[v] = h[v];

    st[v] = tme;
    tme++;

    // cout << "Running dfs on " << v << endl;

    for (auto [id, u] : g[v]){
        if (id == prev) continue;

        if (!vis[u]){
            h[u] = h[v] + 1;
            dfs(u, id);
            mnh[v] = min(mnh[v], mnh[u]);

            if (mnh[u] > h[v]){ // (v, u) is a bridge
                // cout << u << " " << v << endl;
                // cout << v << " -- " << u << " is a bridge." << endl;
                for (auto [x, y] : important){
                    bool A = in_sub(x, u);
                    bool B = in_sub(y, u);

                    // cout << x << " " << y << " " << u << " " << A << " " << B << endl;

                    if (A and !B){
                        // u to v
                        if (edges[id].first == u)
                            s[id] = 'R';
                        else
                            s[id] = 'L';
                    }
                    if (!A and B){
                        // v to u
                        if (edges[id].first == v)
                            s[id] = 'R';
                        else
                            s[id] = 'L';
                    }
                }
            }
            else
                s[id] = 'B';
        }
        else
            mnh[v] = min(mnh[v], h[u]);
    }
    ft[v] = tme;
}

int main(){
    cin >> n >> m;

    for (int i=0; i<m; i++){
        int u, v;
        cin >> u >> v;

        s += 'B';
        edges.push_back({u, v});
        if (u == v)
            continue;

        g[u].push_back({i, v});
        g[v].push_back({i, u});

    }

    for (int i=1; i<=n; i++)
        h[i] = mnh[i] = n + 100;

    cin >> p;
    for (int i=0; i<p; i++){
        int u, v;
        cin >> u >> v;

        if (u == v) continue;
        important.push_back({u, v});
    }

    for (int v = 1; v <= n; v++)
        if (!vis[v])
            dfs(v);

    cout << s << endl;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2652 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 1 ms 2648 KB Output is correct
8 Correct 1 ms 2652 KB Output is correct
9 Correct 1 ms 2652 KB Output is correct
10 Correct 1 ms 2648 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2652 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 1 ms 2648 KB Output is correct
8 Correct 1 ms 2652 KB Output is correct
9 Correct 1 ms 2652 KB Output is correct
10 Correct 1 ms 2648 KB Output is correct
11 Correct 52 ms 8144 KB Output is correct
12 Correct 57 ms 9232 KB Output is correct
13 Correct 59 ms 10404 KB Output is correct
14 Correct 66 ms 11208 KB Output is correct
15 Correct 67 ms 11316 KB Output is correct
16 Correct 59 ms 9096 KB Output is correct
17 Correct 85 ms 10924 KB Output is correct
18 Correct 71 ms 9064 KB Output is correct
19 Correct 74 ms 12228 KB Output is correct
20 Correct 57 ms 8900 KB Output is correct
21 Correct 56 ms 8384 KB Output is correct

Subtask #3
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2652 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 1 ms 2648 KB Output is correct
8 Correct 1 ms 2652 KB Output is correct
9 Correct 1 ms 2652 KB Output is correct
10 Correct 1 ms 2648 KB Output is correct
11 Correct 52 ms 8144 KB Output is correct
12 Correct 57 ms 9232 KB Output is correct
13 Correct 59 ms 10404 KB Output is correct
14 Correct 66 ms 11208 KB Output is correct
15 Correct 67 ms 11316 KB Output is correct
16 Correct 59 ms 9096 KB Output is correct
17 Correct 85 ms 10924 KB Output is correct
18 Correct 71 ms 9064 KB Output is correct
19 Correct 74 ms 12228 KB Output is correct
20 Correct 57 ms 8900 KB Output is correct
21 Correct 56 ms 8384 KB Output is correct
22 Execution timed out 3059 ms 12888 KB Time limit exceeded
23 Halted 0 ms 0 KB -