Submission #1258619

#	Time	Username	Problem	Language	Result	Execution time	Memory
1258619		chikien2009	Pipes (CEOI15_pipes)	C++20	100 / 100	545 ms	13424 KiB

pipes

#include <bits/stdc++.h>

using namespace std;

void setup()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

struct DSU
{
    int par[100000], sz[100000];
    inline DSU()
    {
        for (int i = 0; i < 1e5; ++i)
        {
            par[i] = i;
            sz[i] = 1;
        }
    }
    inline int Get(int inp)
    {
        return (inp == par[inp] ? inp : par[inp] = Get(par[inp]));
    }
    inline bool Combine(int ina, int inb)
    {
        ina = Get(ina);
        inb = Get(inb);
        if (ina != inb)
        {
            if (sz[ina] < sz[inb])
            {
                swap(ina, inb);
            }
            sz[ina] += sz[inb];
            par[inb] = ina;
            return true;
        }
        return false;
    }
} dsu1, dsu2;

int n, m, a, b, c, d = 0;
int head[100000], near[100000];
vector<pair<int, int>> g[100000];

inline void DFS(int node, int last)
{
    head[node] = near[node] = a++;
    for (auto & i : g[node])
    {
        if (i.second != last)
        {
            if (head[i.first] == 0)
            {
                DFS(i.first, i.second);
                if (near[i.first] > head[node])
                {
                    cout << i.first + 1 << " " << node + 1 << "\n";
                }
            }
            near[node] = min(near[node], near[i.first]);
        }
    }
}

int main()
{
    setup();

    cin >> n >> m;
    while (m--)
    {
        cin >> a >> b;
        a--;
        b--;
        c = 0;
        if (dsu1.Get(a) != dsu1.Get(b))
        {
            c += dsu1.Combine(a, b);
        }
        else
        {
            c += dsu2.Combine(a, b);
        }
        if (c > 0)
        {
            g[a].push_back({b, d});
            g[b].push_back({a, d++});
        }
    }
    for (int i = 0; i < n; ++i)
    {
        if (head[i] == 0)
        {
            a = 1;
            DFS(i, -1);
        }
    }
    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