Submission #680459

#	Time	Username	Problem	Language	Result	Execution time	Memory
680459		danikoynov	Pipes (CEOI15_pipes)	C++14	60 / 100	355 ms	11220 KiB

pipes

/**
 ____ ____ ____ ____ ____ ____
||l |||e |||i |||n |||a |||d ||
||__|||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|/__\|

**/

#include<bits/stdc++.h>
#define endl '\n'

using namespace std;
typedef long long ll;

void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

const int maxn = 7e4 + 10;


int n, m;
int par1[maxn], par2[maxn];
int find_leader1(int v)
{
    if (v == par1[v])
        return v;
    return (par1[v] = find_leader1(par1[v]));
}

bool connected1(int v, int u)
{
    v = find_leader1(v);
    u = find_leader1(u);

    if (v == u)
        return true;
    par1[u] = v;
    return false;
}


int find_leader2(int v)
{
    if (v == par2[v])
        return v;
    return (par2[v] = find_leader2(par2[v]));
}
bool connected2(int v, int u)
{
    v = find_leader2(v);
    u = find_leader2(u);
    if (v == u)
        return true;

    par2[u] = v;
    return false;
}

vector < int > g[maxn];
int tin[maxn], low[maxn], timer;
void dfs(int v, int p)
{
    tin[v] = low[v] = ++ timer;
    ///cout << v << " : " << p << " " << g[v].size() << endl;
    bool tf = false;
    for (int u : g[v])
    {
        if (u == p && !tf)
        {
            tf = true;
            continue;
        }

        if (tin[u] != 0)
        {
            low[v] = min(low[v], tin[u]);
        }
        else
        {
            dfs(u, v);
            if (low[u] > tin[v])
                cout << v << " " << u << endl;
            low[v] = min(low[v], low[u]);
        }
    }
}
void solve()
{
    cin >> n >> m;
    int v, u;
    for (int i = 1; i <= n; i ++)
        par1[i] = i, par2[i] = i;
    for (int i = 1; i <= m; i ++)
    {
        cin >> v >> u;
        if (connected1(v, u))
        {
            if (!connected2(v, u))
             {
                 g[v].push_back(u);
                 g[u].push_back(v);
             }
        }
        else
        {
            g[v].push_back(u);
            g[u].push_back(v);
        }
    }


    for (int i = 1; i <= n; i ++)
        if (tin[i] == 0)
            dfs(i, 0);
}

int main()
{
    speed();
    solve();
    return 0;
}

/**
3 2
1 2
2 3
*/

• 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: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10