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Submission #873162

# Submission time Handle Problem Language Result Execution time Memory
873162 2023-11-14T14:41:04 Z Ghulam_Junaid Pipes (CEOI15_pipes) C++17
0 / 100
 882 ms 3672 KB 
#include <bits/stdc++.h>
using namespace std;

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

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

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

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

    h[r1] = r2;

    edges++;
    // g[v].push_back({u, edges});
    // g[u].push_back({v, edges});
}

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

    if (r1 == r2)
        return;

    mnh[r1] = r2;

    edges++;
    // g[v].push_back({u, edges});
    // g[u].push_back({v, edges});
}

void dfs(int v, pair<int, int> prev = {-1, -1}){
    vis[v] = 1;
    if (prev.first == -1)
        h[v] = 0;
    mnh[v] = h[v];

    for (auto& [u, id] : g[v]){
         if (prev.first == u and prev.second == id)
            continue;

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

        if (vis[u])
            continue;

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

        if (mnh[u] >= h[u])
            printf("%d %d\n", u, v);
            
    }
}

int main(){

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

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

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

        if (root1(u) != root1(v))
            merge1(u, v);
        else if (root2(u) != root2(v))
            merge2(u, v);
    }

    if (edges > 2 * N){
        exit(-1);
        return 0;
    }

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

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

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:70:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
pipes.cpp:77:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   77 |         scanf("%d%d", &u, &v);
      |         ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

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

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 3 ms 2648 KB Wrong number of edges
2 Halted 0 ms 0 KB -

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 88 ms 2652 KB Output is correct
2 Incorrect 83 ms 2796 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 170 ms 2848 KB Output is correct
2 Incorrect 161 ms 2848 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 225 ms 2908 KB Output is correct
2 Incorrect 205 ms 3152 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 276 ms 3164 KB Output is correct
2 Incorrect 274 ms 3316 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 446 ms 3392 KB Output is correct
2 Incorrect 452 ms 3392 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 574 ms 3540 KB Output is correct
2 Incorrect 594 ms 3672 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 720 ms 3544 KB Output is correct
2 Incorrect 683 ms 3664 KB Wrong number of edges
3 Halted 0 ms 0 KB -

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 882 ms 3512 KB Output is correct
2 Incorrect 879 ms 3548 KB Wrong number of edges
3 Halted 0 ms 0 KB -