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Submission #872690

# Submission time Handle Problem Language Result Execution time Memory
872690 2023-11-13T15:02:56 Z Ghulam_Junaid Pipes (CEOI15_pipes) C++17
0 / 100
 912 ms 65536 KB 
#include <bits/stdc++.h>
using namespace std;

const int N = 1e5 + 10;
int par1[N], par2[N], h[N], mnh[N];
bool vis[N];
vector<int> g[N];
vector<pair<int, int>> bridges;

int root1(int v){
    return (par1[v] == -1 ? v : par1[v] = root1(par1[v]));
}

int root2(int v){
    return (par2[v] == -1 ? v : par2[v] = root2(par2[v]));
}

void merge1(int u, int v){    
    int r1 = root1(v);
    int r2 = root1(u);

    par1[r1] = r2;

    g[v].push_back(u);
    g[u].push_back(v);
}

void merge2(int u, int v){
    int r1 = root2(u);
    int r2 = root2(v);

    if (r1 == r2)
        return;

    par2[r1] = r2;

    g[v].push_back(u);
    g[u].push_back(v);
}

void dfs(int v, int p = -1){
    vis[v] = 1;
    mnh[v] = h[v];
    for (int u : g[v]){
        if (vis[u]){
            if (u != p)
                mnh[v] = min(mnh[v], h[u]);
            continue;
        }

        h[u] = h[v] + 1;
        dfs(u, v);
        mnh[v] = min(mnh[v], mnh[u]);

        if (mnh[u] >= h[u])
            bridges.push_back({u, v});
    }
}

int main(){
    int n, m;
    scanf("%d%d", &n, &m);

    for (int i=1; i<=n; i++)
        par1[i] = par2[i] = -1;

    for (int i=0; i<m; i++){
        int u, v;
        scanf("%d%d", &u, &v);

        if (root1(u) == root1(v))
            merge2(u, v);
        else
            merge1(u, v);
    }

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

    for (auto [u, v] : bridges)
        printf("%d %d\n", u, v);
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:62:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
pipes.cpp:69:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |         scanf("%d%d", &u, &v);
      |         ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2652 KB Output is correct
2 Incorrect 1 ms 2652 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 3420 KB Output is correct
2 Incorrect 4 ms 3164 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 84 ms 8448 KB Output is correct
2 Incorrect 82 ms 8188 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 139 ms 13396 KB Wrong number of edges
2 Halted 0 ms 0 KB -

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 230 ms 21588 KB Memory limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 308 ms 31984 KB Memory limit exceeded
2 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 456 ms 45084 KB Memory limit exceeded
2 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 608 ms 57940 KB Memory limit exceeded
2 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 743 ms 65536 KB Memory limit exceeded
2 Halted 0 ms 0 KB -

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 912 ms 65536 KB Memory limit exceeded
2 Halted 0 ms 0 KB -