Submission #573493

#	Time	Username	Problem	Language	Result	Execution time	Memory
573493		vladislav11	Pipes (CEOI15_pipes)	C++14	0 / 100	2148 ms	23432 KiB

pipes

#include <bits/stdc++.h>

using namespace std;

const int N = 1e5+10;

int leader[N];
int ssize[N];

int get_leader ( int v )
{
    if ( leader[v] == v )
        return v;

    leader[v] = get_leader( leader[v] );

    return leader[v];
}

vector< pair<int,int> > adj[N];
int a[N];

int jmp[N];
int par[N];
int depth[N];

int lca ( int u, int v )
{
    if ( u == v )
        return u;

    if ( depth[u] > depth[v] )
        swap( u, v );

    while ( depth[u] < depth[v] )
    {
        if ( depth[u] <= depth[ jmp[v] ] )
            v = jmp[v];
        else
            v = par[v];
    }

    while ( u != v )
    {
        if ( jmp[u] != jmp[v] )
        {
            u = jmp[u];
            v = jmp[v];
        }
        else
        {
            u = par[u];
            v = par[v];
        }
    }

    return v;
}

void add_leaf ( int v, int p )
{
    depth[v] = depth[p] + 1;
    par[v] = p;

    if ( jmp[p] == -1 || jmp[ jmp[p] ] == -1 )
        jmp[v] = p;

    else if ( depth[p] - depth[ jmp[p] ] == depth[ jmp[p] ] - depth[ jmp[ jmp[p] ] ] )
        jmp[v] = jmp[ jmp[p] ];

    else
        jmp[v] = p;
}

void dfs_build_jmp ( int v, int p )
{
    add_leaf( v, p );

    for ( auto& [to,w] : adj[v] )
    if ( to != p )
        dfs_build_jmp( to, v );
}

int dfs_a ( int v, int p )
{
    for ( auto& [to,w] : adj[v] )
    if ( to != p )
    {
        int res = dfs_a( to, v );

        a[v] += res;

        if ( res )
            w = 1;
    }

    int res = a[v];
    a[v] = 0;

    return res;
}

int main ()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n, m;
    cin >> n >> m;

    for ( int i=1; i<=n; i++ )
    {
        leader[i] = i;
        ssize[i] = 1;

        adj[i].clear();
        a[i] = 0;

        jmp[i] = par[i] = -1;
        depth[i] = 1;
    }

    while ( m-- )
    {
        int u, v;
        cin >> u >> v;

        int lu = get_leader( u );
        int lv = get_leader( v );

        if ( lu == lv )
        {
            int w = lca( u, v );

            a[u]++;
            a[v]++;
            a[w] -= 2;

            continue;
        }

        if ( ssize[lu] < ssize[lv] )
        {
            swap( lu, lv );
            swap( u, v );
        }

        dfs_a( lv, -1 );

        dfs_build_jmp( v, u );

        adj[u].push_back({ v, 0 });
        adj[v].push_back({ u, 0 });

        leader[lv] = lu;
        ssize[lu] += ssize[lv];
    }

    for ( int i=1; i<=n; i++ )
    if ( leader[i] == i )
        dfs_a( i, -1 );

    for ( int i=1; i<=n; i++ )
    for ( auto& [to,w] : adj[i] )
    if ( !w && i < to )
        cout << i << ' ' << to << '\n';

    return 0;
}

Compilation message (stderr)

pipes.cpp: In function 'void dfs_build_jmp(int, int)':
pipes.cpp:79:17: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   79 |     for ( auto& [to,w] : adj[v] )
      |                 ^
pipes.cpp: In function 'int dfs_a(int, int)':
pipes.cpp:86:17: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   86 |     for ( auto& [to,w] : adj[v] )
      |                 ^
pipes.cpp: In function 'int main()':
pipes.cpp:164:17: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  164 |     for ( auto& [to,w] : adj[i] )
      |                 ^

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
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• Subtask 10: 0 / 10