Submission #1305913

#	Time	Username	Problem	Language	Result	Execution time	Memory
1305913		Zbyszek99	Capital City (JOI20_capital_city)	C++20	100 / 100	473 ms	38520 KiB

capital_city

#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;

int ans = 1e9;
ll color[200001];
vi graph[200001];
int sub[200001];
bool odw[200001];

bool was[200001];
bool was_color[200001];
int up_vert[200001];
vl color_ls[200001];
int color_cnt[200001];
vi ls;

void dfs_sub(int v, int pop)
{
    up_vert[v] = pop;
    ls.pb(v);
    sub[v] = 1;
    forall(it,graph[v])
    {
        if(odw[it] || it == pop) continue;
        dfs_sub(it,v);
        sub[v] += sub[it];
    }
}

void centroid(int v, int n)
{
    int pop = -1;
    dfs_sub(v,v);
    while(true)
    {
        pii best = {-1,-1};
        forall(it,graph[v])
        {
            if(odw[it] || it == pop) continue;
            best = max(best,{sub[it],it});
        }
        if(best.ff > n/2)
        {
            pop = v;
            v = best.ss;
        }
        else break;
    }
    odw[v] = 1;
    ls = {};
    dfs_sub(v,v);
    int cur_ans = 0;
    queue<int> q;
    forall(it,ls) 
    {
        color_cnt[color[it]]++;
        if(color[it] == color[v]) q.push(it);
        was[it] = 0;
        was_color[color[it]] = 0;
    }
    was[v] = 1;
    was_color[color[v]] = 1;
    if(color_cnt[color[v]] != siz(color_ls[color[v]])) goto first_time_i_use_this_shit_xd;
    while(!q.empty())
    {
        int t = q.front();
        q.pop();
        while(!was[t])
        {
            was[t] = 1;
            if(color_cnt[color[t]] != siz(color_ls[color[t]])) goto first_time_i_use_this_shit_xd;
            if(!was_color[color[t]]) 
            {
                cur_ans++;
                forall(it,color_ls[color[t]]) q.push(it);
                was_color[color[t]] = 1;
            }
            t = up_vert[t];
        }
    }
    ans = min(ans,cur_ans);
    first_time_i_use_this_shit_xd:
    ls = {};
    dfs_sub(v,v);
    forall(it,ls) color_cnt[color[it]] = 0;
    forall(it,graph[v]) if(!odw[it]) centroid(it,sub[it]);
}

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //random_start();
    int n,k;
    cin >> n >> k;
    rep(i,n-1)
    {
        int a,b;
        cin >> a >> b;
        graph[a].pb(b);
        graph[b].pb(a);
    }
    rep2(i,1,n) cin >> color[i];
    rep2(i,1,n) color_ls[color[i]].pb(i);
    centroid(1,n);
    cout << ans;
}

• Subtask 1: 1 / 1
• Subtask 2: 10 / 10
• Subtask 3: 30 / 30
• Subtask 4: 59 / 59