oj.uz

Submission #216329

# Submission time Handle Problem Language Result Execution time Memory
216329 2020-03-27T06:12:57 Z zscoder Capital City (JOI20_capital_city) C++17
11 / 100
 3000 ms 57440 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fbo find_by_order
#define ook order_of_key
 
typedef long long ll;
typedef pair<int,int> ii;
typedef vector<int> vi;
typedef long double ld; 
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update> pbds;

vi adj[222222];
int sub[222222];
int color[222222];
vector<set<int> > cities;
set<int> usedcolors;
int colorcnt[222222];
int ans=int(1e9);
int banned[222222]; //banned colors
bool cenvisited[222222];
set<int> cursub; //current subtree elements

void prep(int u, int p=-1)
{
	sub[u]=1;	
	colorcnt[color[u]]++;
	usedcolors.insert(color[u]);
	cursub.insert(u);
	for(int v:adj[u])
	{
		if(v==p) continue;
		if(cenvisited[v]) continue;
		prep(v,u);
		sub[u]+=sub[v];
	}
}

int centroid(int u, int p=-1, int r=-1)
{
	for(int v:adj[u])
	{
		if(v==p) continue;
		if(cenvisited[v]) continue;
		if(sub[v]*2>sub[r])
		{
			return centroid(v,u,r);
		}
	}
	return u;
}

bool valid(int c) //is a color valid in this subtree
{
	return (int(cities[c].size())==colorcnt[c]);
}

set<int> colorset;
set<int> processed;

void push(int c)
{
	if(colorset.find(c)==colorset.end()&&processed.find(c)==processed.end())
	{
		colorset.insert(c);
	}
}

int h[222222];
int par[222222];

void calch(int u, int p=-1)
{
	for(int v:adj[u])
	{
		if(v==p) continue;
		if(cenvisited[v]) continue;
		par[v]=u;
		h[v]=h[u]+1;
		calch(v,u);
	}
}


struct DSU
{
	int S;
	
	struct node
	{
		int p, rt;
	};
	vector<node> dsu;
	
	DSU(int n)
	{
		S = n;
		for(int i = 0; i < n; i++)
		{
			node tmp;
			tmp.p = i; tmp.rt = i;
			dsu.pb(tmp);
		}
	}
	void reset(int n)
	{
		dsu.clear();
		S = n;
		for(int i = 0; i < n; i++)
		{
			node tmp;
			tmp.p = i; tmp.rt = i;
			dsu.pb(tmp);
		}
	}
	
	void resetnode(int u)
	{
		dsu[u].p = u;
		dsu[u].rt = u;
	}
	
	int rt(int u)
	{
		if(dsu[u].p == u) return u;
		dsu[u].p = rt(dsu[u].p);
		return dsu[u].p;
	}
	
	void merge(int u, int v)
	{
		u = rt(u); v = rt(v);
		if(u == v) return ;
		if(rand()&1) swap(u, v);
		dsu[v].p = u;
		if(h[dsu[v].rt]<h[dsu[u].rt])
		{
			dsu[u].rt=dsu[v].rt;
		}
	}
	
	bool sameset(int u, int v)
	{
		if(rt(u) == rt(v)) return true;
		return false;
	}
	
	int getrt(int u)
	{
		return dsu[rt(u)].rt;
	}
};
DSU dsu(1);

void solve(int u)
{
	prep(u);
	int cent = centroid(u,-1,u);
	h[cent]=0; par[cent]=-1;
	calch(cent);
	//solve for this centroid
	colorset.insert(color[cent]);
	bool pos=1;
	while(!colorset.empty())
	{
		int c = (*colorset.begin()); processed.insert(c); colorset.erase(c);
		if(!valid(c)){pos=0; break;} //invalid color found
		//let's push all the stuff of this color
		for(int u:cities[c])
		{
			while(u!=cent)
			{
				u=dsu.getrt(u);
				if(u==cent) break;
				push(color[par[u]]);
				dsu.merge(par[u],u);
				u=par[u];
			}
		}
	}
	/*
	cerr<<"SOLVE WITH CENTROID = "<<cent<<'\n';
	cerr<<"POSSIBLE = "<<pos<<'\n';
	if(pos)
	{
		cerr<<"PROCESSED = ";
		for(int x:processed) cerr<<x<<' ';
		cerr<<'\n';
	}
	*/
	for(int x:cursub)
	{
		dsu.resetnode(x);
	}
	if(pos)
	{
		ans=min(ans,int(processed.size()));
	}
	cenvisited[cent]=1;
	for(int x:usedcolors) colorcnt[x]=0;
	usedcolors.clear();
	colorset.clear();
	processed.clear();
	cursub.clear();
	for(int v:adj[cent])
	{
		if(cenvisited[v]) continue;
		//recurse
		solve(v);
	}
}

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	int n,k; cin>>n>>k;
	dsu.reset(n);
	for(int i=0;i<n-1;i++)
	{
		int u,v; cin>>u>>v; u--; v--;
		adj[u].pb(v); adj[v].pb(u);
	}
	cities.resize(k);
	for(int i=0;i<n;i++)
	{
		cin>>color[i]; color[i]--;
		cities[color[i]].insert(i);
	}
	solve(0);
	cout<<ans-1<<'\n'; //# of cities - 1
}

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 5632 KB Output is correct
2 Correct 8 ms 5632 KB Output is correct
3 Correct 7 ms 5632 KB Output is correct
4 Correct 7 ms 5632 KB Output is correct
5 Correct 8 ms 5680 KB Output is correct
6 Correct 10 ms 5632 KB Output is correct
7 Correct 8 ms 5632 KB Output is correct
8 Correct 7 ms 5632 KB Output is correct
9 Correct 7 ms 5632 KB Output is correct
10 Correct 9 ms 5632 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 5632 KB Output is correct
2 Correct 8 ms 5632 KB Output is correct
3 Correct 7 ms 5632 KB Output is correct
4 Correct 7 ms 5632 KB Output is correct
5 Correct 8 ms 5680 KB Output is correct
6 Correct 10 ms 5632 KB Output is correct
7 Correct 8 ms 5632 KB Output is correct
8 Correct 7 ms 5632 KB Output is correct
9 Correct 7 ms 5632 KB Output is correct
10 Correct 9 ms 5632 KB Output is correct
11 Correct 14 ms 6016 KB Output is correct
12 Correct 14 ms 6016 KB Output is correct
13 Correct 12 ms 5888 KB Output is correct
14 Correct 13 ms 5888 KB Output is correct
15 Correct 18 ms 6016 KB Output is correct
16 Correct 18 ms 6016 KB Output is correct
17 Correct 11 ms 6016 KB Output is correct
18 Correct 12 ms 6016 KB Output is correct
19 Correct 12 ms 6016 KB Output is correct
20 Correct 12 ms 5992 KB Output is correct
21 Correct 12 ms 6016 KB Output is correct
22 Correct 13 ms 6144 KB Output is correct
23 Correct 14 ms 6016 KB Output is correct
24 Correct 15 ms 6016 KB Output is correct
25 Correct 15 ms 6016 KB Output is correct
26 Correct 17 ms 6144 KB Output is correct
27 Correct 15 ms 6016 KB Output is correct
28 Correct 17 ms 6016 KB Output is correct
29 Correct 15 ms 6016 KB Output is correct
30 Correct 14 ms 6016 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Execution timed out 3085 ms 57440 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 59.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 5632 KB Output is correct
2 Correct 8 ms 5632 KB Output is correct
3 Correct 7 ms 5632 KB Output is correct
4 Correct 7 ms 5632 KB Output is correct
5 Correct 8 ms 5680 KB Output is correct
6 Correct 10 ms 5632 KB Output is correct
7 Correct 8 ms 5632 KB Output is correct
8 Correct 7 ms 5632 KB Output is correct
9 Correct 7 ms 5632 KB Output is correct
10 Correct 9 ms 5632 KB Output is correct
11 Correct 14 ms 6016 KB Output is correct
12 Correct 14 ms 6016 KB Output is correct
13 Correct 12 ms 5888 KB Output is correct
14 Correct 13 ms 5888 KB Output is correct
15 Correct 18 ms 6016 KB Output is correct
16 Correct 18 ms 6016 KB Output is correct
17 Correct 11 ms 6016 KB Output is correct
18 Correct 12 ms 6016 KB Output is correct
19 Correct 12 ms 6016 KB Output is correct
20 Correct 12 ms 5992 KB Output is correct
21 Correct 12 ms 6016 KB Output is correct
22 Correct 13 ms 6144 KB Output is correct
23 Correct 14 ms 6016 KB Output is correct
24 Correct 15 ms 6016 KB Output is correct
25 Correct 15 ms 6016 KB Output is correct
26 Correct 17 ms 6144 KB Output is correct
27 Correct 15 ms 6016 KB Output is correct
28 Correct 17 ms 6016 KB Output is correct
29 Correct 15 ms 6016 KB Output is correct
30 Correct 14 ms 6016 KB Output is correct
31 Execution timed out 3085 ms 57440 KB Time limit exceeded
32 Halted 0 ms 0 KB -