Submission #52625

#	Time	Username	Problem	Language	Result	Execution time	Memory
52625		Alexa2001	Pipes (CEOI15_pipes)	C++17	100 / 100	1213 ms	14044 KiB

pipes

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const int Nmax = 1e5 + 5;

int n, m, i, x, y;
int level[Nmax], low[Nmax];
vector<int> v[Nmax];

struct Forest
{
    int t[Nmax];

    void clear()
    {
        int i;
        for(i=1; i<=n; ++i) t[i] = i;
    }

    int boss(int x)
    {
        if(t[x] == x) return x;
        return t[x] = boss(t[x]);
    }

    void unite(int x, int y)
    {
        x = boss(x), y = boss(y);
        t[x] = y;
    }
} A, B;

void solve(int node, int dad = 0)
{
    level[node] = low[node] = level[dad] + 1;

    bool ok = 0;
    for(auto son : v[node])
    {
        if(son == dad && !ok)
        {
            ok = 1;
            continue;
        }

        if(level[son])
        {
            low[node] = min(low[node], level[son]);
            continue;
        }

        solve(son, node);
        low[node] = min(low[node], low[son]);

        if(low[son] == level[son])
            cout << node << ' ' << son << '\n';
    }
}

int main()
{
  //  freopen("input", "r", stdin);
  //  freopen("output", "w", stdout);
    cin.sync_with_stdio(false);

    cin >> n >> m;
    A.clear(); B.clear();

    while(m--)
    {
        cin >> x >> y;
        if(B.boss(x) == B.boss(y)) continue; /// same bcomp

        if(A.boss(x) != A.boss(y)) A.unite(x, y);
            else B.unite(x, y);

        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(i=1; i<=n; ++i)
        if(!level[i]) solve(i);

    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10