Submission #982476

#	Time	Username	Problem	Language	Result	Execution time	Memory
982476		shadow_sami	Capital City (JOI20_capital_city)	C++17	100 / 100	486 ms	69952 KiB

capital_city

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long int ll;
typedef vector<ll> vi;
typedef vector<vector<ll>> vvi;
typedef pair<ll,ll> pi;
typedef map<ll,ll> mi;
typedef long double ld;
typedef vector<ld> vd;
typedef vector<vector<ld>> vvd;
typedef pair<ld,ld> pd;
#define ff first
#define ss second
#define srt(a) sort(a.begin(),a.end());
#define fip(k, n) for (ll i = k; i < n; i++)
#define fjp(k, n) for (ll j = k; j < n; j++)
#define fin(k, n) for (ll i = k; i >= n; i--)
#define fjn(k, n) for (ll j = k; j >= n; j--)
#define fp(k, n, m) for (ll k = n; k < m; k++)
#define fn(k, n, m) for (ll k = n; k >= m; k--)
#define ordered_set tree<pi, null_type,less< pi >, rb_tree_tag,tree_order_statistics_node_update>
#define totalOne(n) __builtin_popcount(n)
#define backZero(n) __builtin_ctzll(n)
#define frontZero(n) __builtin_clzll(n)
#define fx(k) for ( auto x : k )
#define test ll t;cin >> t;while (t--)
#define nli "\n"

// ==========================(debug)============================================================================================== //

#ifndef ONLINE_JUDGE
#define debug(x) cerr << #x <<" "; _printn(x); cerr << nli;
#else
#define debug(x)
#endif

void _printn(ll x){ cerr<<x<<" "; }
void _printn(int x){ cerr<<x<<" "; }
void _printn(ld x){ cerr<<x<<" "; }
void _printn(double x){ cerr<<x<<" "; }
void _printn(string x){ cerr<<x<<" "; }
void _printn(char x){ cerr<<x<<" "; }
void _printn(bool x){ cerr<<x<<" "; }
template<class T,class V>void _printn(pair<T,V> vv);
template<class T> void _printn(vector<T> vv);
template<class T> void _printn(set<T> vv);
template<class T,class V> void _printn(map<T,V> vv);
template<class T> void _printn(multiset<T> vv);
template<class T,class V>void _printn(pair<T,V> vv){ cerr<<"( ";_printn(vv.ff);cerr<<",";_printn(vv.ss);cerr<<")";}
template<class T> void _printn(vector<T> vv){ cerr<<"[ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"]"; };
template<class T> void _printn(set<T> vv){ cerr<<"{ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"}"; };
template<class T> void _printn(multiset<T> vv){ cerr<<"{ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"}"; };
template<class T,class V> void _printn(map<T,V> vv){ cerr<<"{ "; for(auto xx:vv){ _printn(xx);cerr<<" "; } cerr<<"}"; };

// ==========================(debug)============================================================================================== //

ll n,m,tp,tp2,res,cnt,sum,tptp,ans;
const ll mx = 5e5+5;
const ll mod = 1e9+7;

// ==========================(MOD)=============================================================================================== //

ll mod_add(ll aa,ll bb){ return ((aa%mod)+(bb%mod))%mod; }
ll mod_minus(ll aa,ll bb){ return (((aa%mod)-(bb%mod))+10*mod)%mod; }
ll mod_mul(ll aa,ll bb){ return ((aa%mod)*(bb%mod))%mod; }
ll mod_power(ll aa,ll bb){ aa%=mod; ll empowered = 1; bb%=mod-1; while(bb > 0){ if(bb & 1) empowered = mod_mul(empowered,aa); bb = bb >> 1; aa = mod_mul(aa,aa); } return empowered; }
ll mod_divi(ll aa,ll bb){ aa=mod_mul(aa,mod_power(bb,mod-2)); return aa; }

// ==========================(MOD)=============================================================================================== //

bool f = false;
ll a[mx];
vi adj[mx];
ll up[mx];
vi lis[mx];
bool is2[mx];
bool is[mx];
bool mark[mx];
bool cc[mx];
queue<ll> q;
ll sz[mx];
vi v;

void emptify(){
	while(q.size())
		q.pop();
	return;
}

void dfs(ll u,ll par){
	v.push_back(u);
	up[u] = par;
	sz[u] = 1;
	fx(adj[u])
		if(x!=par && !mark[x]){
			dfs(x,u);
			sz[u] += sz[x];
		}
	return;
}

ll get(ll u,ll par,ll d){
	fx(adj[u])
		if(x!=par && !mark[x] && 2*sz[x]>d)
			return get(x,u,d);
	return u;
}

void divide(ll u){		
	dfs(u,u);
	u = get(u,u,sz[u]);
	v.clear();
	dfs(u,u);	
	mark[u] = 1;
	fx(v)
		cc[x] = 1;
	res = 0;
	emptify();
	q.push(a[u]); 
	f = 1;	
	while(q.size()){
		auto it = q.front();        				
		q.pop();
		if(is2[it])
			continue;
		is2[it] = 1;
		res++;
		fx(lis[it]){
			is[x] = 1;
			if(!cc[x]){
				f = 0;
				break;
			}
			if(a[up[x]] != a[x] && !is2[a[up[x]]])
				q.push(a[up[x]]);        			
		}        	
		if(!f)	        		
			break;
	}
	if(f)
		ans = min(ans,res-1);	
	fx(v){
		cc[x] = 0;
		is[x] = 0;
		is2[a[x]] = 0;		
	}
	fx(adj[u])
		if(!mark[x])
			divide(x);
	return;	
}



int main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    // #ifndef ONLINE_JUDGE
        // freopen("input1.txt", "r", stdin);
        // freopen("output1.txt", "w", stdout);
        // freopen("error1.txt", "w", stderr);
    // #endif // ONLINE_JUDGE

        cin>>n>>m;
        ll sr,de;
        fip(0,n-1){
        	cin>>sr>>de;
        	adj[sr].push_back(de);
        	adj[de].push_back(sr);
        }
        fip(1,n+1)	{
        	cin>>a[i];
        	lis[a[i]].push_back(i);
        }
        ans = 1e18;
        divide(1);
        cout<<ans<<nli;
        
    cerr << "Time elapsed: " << setprecision(6) << 1000.0 * clock() / CLOCKS_PER_SEC << "ms\n";
    return 0;
}

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