oj.uz

Submission #328550

# Submission time Handle Problem Language Result Execution time Memory
328550 2020-11-17T04:46:43 Z YJU Capital City (JOI20_capital_city) C++14
1 / 100
 835 ms 60652 KB 
#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
const ll MOD=1e9+7;
const ll MOD2=998244353;
const ll N=4e5+5;
const ll K=350;
const ld pi=3.14159265359;
const ll INF=(1LL<<40);
#define SQ(i) ((i)*(i))
#define REP(i,n) for(ll i=0;i<n;i++)
#define REP1(i,n) for(ll i=1;i<=n;i++)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define setp setprecision
#define lwb lower_bound
#define SZ(_a) (ll)_a.size()

ll n,m,x,y,col[N],maxn[N],vis[N],sub[N],vis_col[N],ans=INF;
vector<ll> v[N],C[N];
ll pa[N],tag[N];

ll Find_root(ll nd){
	function<void(ll,ll)> DFS = [&](ll id,ll p){
		sub[id]=1;maxn[id]=-1;
		for(auto i:v[id]){
			if(i!=p&&!vis[i]){
				DFS(i,id);
				sub[id]+=sub[i];
				if(maxn[id]==-1||sub[maxn[id]]<sub[i])maxn[id]=i;
			}
		}
	};
	DFS(nd,0);
	ll tot=sub[nd];
	while(maxn[nd]!=-1&&sub[maxn[nd]]*2>=tot)nd=maxn[nd];
	return nd;
}

void centroid(ll nd){
	ll rt=Find_root(nd);
	function<void(ll,ll)> DFS = [&](ll id,ll p){
		pa[id]=p;tag[id]=rt;
		for(auto i:v[id]){
			if(!vis[i]&&i!=p)DFS(i,id);
		}
	};
	DFS(rt,rt);
	while(pa[rt]!=rt)pa[rt]=rt;
	vector<ll> res;
	queue<ll> q;
	q.push(rt);
	ll cnt=-1,ok=1,u;
	while(SZ(q)&&ok){
		u=q.front();q.pop();
		++cnt;
		while(ok){
			if(tag[u]==0)break;
			if(!vis_col[col[u]]){
				cnt-=SZ(C[col[u]]);
				vis_col[col[u]]=1;
				res.pb(col[u]);
				for(auto i:C[col[u]]){
					q.push(i);
					if(tag[i]!=rt){
						ok=0;break;
					}
				}
			}
			tag[u]=0;
			u=pa[u];
			if(u==rt)break;
		}
	}
	for(auto i:res)vis_col[i]=0;
	if(cnt==0)ans=min(ans,SZ(res)-1);
	vis[u]=1;
	for(auto i:v[u])if(!vis[i])centroid(i);
}

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);
	cin>>n>>m;
	REP1(i,n-1)cin>>x>>y,v[x].pb(y),v[y].pb(x);
	REP1(i,n)cin>>col[i],C[col[i]].pb(i);
	centroid(1);
	cout<<ans<<"\n"; 
	return 0;
}

Compilation message

capital_city.cpp: In function 'void centroid(ll)':
capital_city.cpp:58:17: warning: 'u' may be used uninitialized in this function [-Wmaybe-uninitialized]
   58 |  ll cnt=-1,ok=1,u;
      |                 ^

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 19180 KB Output is correct
2 Correct 12 ms 19180 KB Output is correct
3 Correct 12 ms 19180 KB Output is correct
4 Correct 13 ms 19180 KB Output is correct
5 Correct 12 ms 19180 KB Output is correct
6 Correct 12 ms 19180 KB Output is correct
7 Correct 12 ms 19180 KB Output is correct
8 Correct 12 ms 19180 KB Output is correct
9 Correct 12 ms 19180 KB Output is correct
10 Correct 12 ms 19180 KB Output is correct

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 19180 KB Output is correct
2 Correct 12 ms 19180 KB Output is correct
3 Correct 12 ms 19180 KB Output is correct
4 Correct 13 ms 19180 KB Output is correct
5 Correct 12 ms 19180 KB Output is correct
6 Correct 12 ms 19180 KB Output is correct
7 Correct 12 ms 19180 KB Output is correct
8 Correct 12 ms 19180 KB Output is correct
9 Correct 12 ms 19180 KB Output is correct
10 Correct 12 ms 19180 KB Output is correct
11 Correct 14 ms 19436 KB Output is correct
12 Correct 14 ms 19436 KB Output is correct
13 Correct 14 ms 19436 KB Output is correct
14 Correct 14 ms 19436 KB Output is correct
15 Correct 16 ms 19692 KB Output is correct
16 Correct 15 ms 19456 KB Output is correct
17 Incorrect 14 ms 19436 KB Output isn't correct
18 Halted 0 ms 0 KB -

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 814 ms 60068 KB Output is correct
2 Correct 260 ms 60652 KB Output is correct
3 Correct 796 ms 59500 KB Output is correct
4 Correct 251 ms 60652 KB Output is correct
5 Incorrect 835 ms 55644 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #4
0 / 59.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 19180 KB Output is correct
2 Correct 12 ms 19180 KB Output is correct
3 Correct 12 ms 19180 KB Output is correct
4 Correct 13 ms 19180 KB Output is correct
5 Correct 12 ms 19180 KB Output is correct
6 Correct 12 ms 19180 KB Output is correct
7 Correct 12 ms 19180 KB Output is correct
8 Correct 12 ms 19180 KB Output is correct
9 Correct 12 ms 19180 KB Output is correct
10 Correct 12 ms 19180 KB Output is correct
11 Correct 14 ms 19436 KB Output is correct
12 Correct 14 ms 19436 KB Output is correct
13 Correct 14 ms 19436 KB Output is correct
14 Correct 14 ms 19436 KB Output is correct
15 Correct 16 ms 19692 KB Output is correct
16 Correct 15 ms 19456 KB Output is correct
17 Incorrect 14 ms 19436 KB Output isn't correct
18 Halted 0 ms 0 KB -