Submission #1257780

#	Time	Username	Problem	Language	Result	Execution time	Memory
1257780		Zbyszek99	Pipes (CEOI15_pipes)	C++20	100 / 100	584 ms	10288 KiB

pipes

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

const int maxn = 100001;

int rep_[maxn];
int siz_[maxn];
int rep2[maxn];
int P[maxn];
vi sons[maxn];
int depth[maxn];
vector<pii> ans;

int fint_comp(int v)
{
    if(rep2[v] == v) return v;
    rep2[v] = fint_comp(rep2[v]);
    return rep2[v];
}

int fint(int v)
{
    if(rep_[v] == v) return v;
    rep_[v] = fint(rep_[v]);
    return rep_[v];
}

void onion(int a, int b)
{
    a = fint(a);
    b = fint(b);
    if(a == b) return;
    siz_[b] += siz_[a];
    rep_[a] = b;
}

int nxt;

void dfs_upd(int v, int pop, int d)
{
    depth[v] = d;
    P[v] = pop;
    rep(i,siz(sons[v]))
    {
        nxt = fint_comp(sons[v][i]);
        if(nxt == v)
        {
            swap(sons[v][siz(sons[v])-1],sons[v][i]);
            sons[v].pop_back();
            i--;
            continue;
        }
        if(nxt != pop)
        {
            dfs_upd(nxt,v,d+1);
        }
    }
}

void onion_comps(int a, int b)
{
    a = fint_comp(a);
    b = fint_comp(b);
    if(siz(sons[a]) > siz(sons[b])) swap(a,b);
    rep2[a] = b;
    forall(it,sons[a])
    {
        sons[b].pb(it);
    }
    sons[a] = {};
}

void add_edge(int a, int b)
{
    if(fint_comp(a) == fint_comp(b)) return;
    if(fint(a) != fint(b))
    {
        ans.pb({a,b});
        int ca = fint(a);
        int cb = fint(b);
        if(siz_[ca] > siz_[cb]) swap(a,b);
        onion(a,b);
        a = fint_comp(a);
        b = fint_comp(b);
        dfs_upd(a,b,depth[b]+1);
        sons[a].pb(b);
        sons[b].pb(a);
    }
    else
    {
        vi con;
        a = fint_comp(a);
        b = fint_comp(b);
        while(a != b)
        {
            if(depth[a] > depth[b])
            {
                con.pb(a);
                a = fint_comp(P[a]);
            }
            else
            {
                con.pb(b);
                b = fint_comp(P[b]);
            }
        }
        con.pb(a);
        int p = P[a];
        int d = depth[a];
        rep(i,siz(con)-1)
        {
            onion_comps(con[i],con[i+1]);
        }
        P[fint_comp(a)] = p;
        depth[fint_comp(a)] = d;
    }
}

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //random_start();
    int n,m;
    cin >> n >> m;
    rep2(i,1,n)
    {
        rep_[i] = i;
        rep2[i] = i;
        siz_[i] = 1;
        depth[i] = 0;
        P[i] = i;
    }
    rep(i,m)
    {
        int a,b;
        cin >> a >> b;
        add_edge(a,b);
    }
    forall(it,ans)
    {
        if(fint_comp(it.ff) != fint_comp(it.ss))
        {
            cout << it.ff << " " << it.ss << "\n";
        }
    }
}

• 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