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Submission #656937

# Submission time Handle Problem Language Result Execution time Memory
656937 2022-11-08T14:19:17 Z benjaminkleyn Pipes (CEOI15_pipes) C++17
40 / 100
 169 ms 17140 KB 
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const int max_n = 100000;

int mem[2 * max_n];

int find(int u, int dsu)
{
    return (mem[max_n * dsu + u] == u ? u : mem[max_n * dsu + u] = find(mem[max_n * dsu + u], dsu));
}

bool same_set(int u, int v, int dsu)
{
    return find(u, dsu) == find(v, dsu);
}

void unite(int u, int v, int dsu)
{
    mem[max_n * dsu + v] = find(u, dsu);
}


int n, m, timer = 0;
vector<int> g[max_n];
int edge_xor[2 * max_n], edge_cnt = 0;

void dfs(int u, int p = -1)
{
    mem[u] = mem[max_n + u] = ++timer;
    for (int e : g[u])
        if (e != p)
        {
            int v = edge_xor[e] ^ u;
            if (mem[v])
                mem[max_n + u] = min(mem[max_n + u], mem[v]);
            else
            {
                dfs(v, e);
                mem[max_n + u] = min(mem[max_n + u], mem[max_n + v]);

                if (mem[max_n + v] > mem[u])
                    cout << u + 1 << ' ' << v + 1 << '\n';
            }
        }
}


int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n >> m;

    for (int i = 0; i < n; i++)
        mem[i] = mem[max_n + i] = i;
    
    for (int i = 0, a ,b; i < m; i++)
    {
        cin >> a >> b;
        a--, b--;

        if (!same_set(a, b, 0))
            unite(a, b, 0);
        else if (!same_set(a, b, 1))
            unite(a, b, 1);
        else continue;

        g[a].push_back(edge_cnt);
        g[b].push_back(edge_cnt);
        edge_xor[edge_cnt] = a ^ b;
        edge_cnt++;
    }

    for (int i = 0; i < n; i++)
        mem[i] = mem[max_n + i] = 0;

    for (int i = 0; i < n; i++)
        if (!mem[i])
            dfs(i);

    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 2 ms 2644 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 3412 KB Output is correct
2 Correct 5 ms 3028 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 80 ms 3980 KB Output is correct
2 Correct 86 ms 3516 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 169 ms 5964 KB Output is correct
2 Correct 165 ms 4880 KB Output is correct

Subtask #5
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 65 ms 13688 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #6
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 79 ms 15716 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #7
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 105 ms 16012 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #8
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 82 ms 16860 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #9
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 97 ms 17140 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -

Subtask #10
0 / 10.0

# Verdict Execution time Memory Grader output
1 Runtime error 82 ms 16648 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -