Submission #217079

#	Time	Username	Problem	Language	Result	Execution time	Memory
217079		Pajaraja	Capital City (JOI20_capital_city)	C++17	100 / 100	729 ms	34296 KiB

capital_city

#include <bits/stdc++.h>
#define MAXN 200007
using namespace std;
int c[MAXN],ccnt[MAXN],p[MAXN],sz,ctr,rez=1000000000,br,n,k;
bool vi[MAXN],vc[MAXN],fas,vb[MAXN];
vector<int> g[MAXN],b[MAXN];
queue<int> q;
void dfssize(int s,int f)
{
	sz++; vi[s]=false; vb[c[s]]=false; ccnt[c[s]]=0;
	for(int i=0;i<g[s].size();i++) if(g[s][i]!=f && !vc[g[s][i]]) dfssize(g[s][i],s);
}
int fndctr(int s,int f)
{
	int sum=1;
	bool mb=true;
	for(int i=0;i<g[s].size();i++)  if(g[s][i]!=f && !vc[g[s][i]])
	{
		int x=fndctr(g[s][i],s);
		if(x>sz/2) mb=false;
		else sum+=x;
	}
	if(sz-sum>sz/2) mb=false;
	if(mb) ctr=s;
	return sum;
}
void dfsctr(int s,int f)
{
	ccnt[c[s]]++;
	p[s]=f;
	for(int i=0;i<g[s].size();i++) if(g[s][i]!=f && !vc[g[s][i]]) dfsctr(g[s][i],s);
}
void dodajboju(int co)
{
	if(vb[co] || fas) return;
	if(ccnt[co]!=b[co].size()) {fas=true; return;}
	vb[co]=true; br++;
	for(int i=0;i<b[co].size();i++) q.push(b[co][i]);
}
void dizanje(int s)
{
	if(vi[s] || fas) return;
	vi[s]=true;
	dodajboju(c[s]);
	dizanje(p[s]);
}
void centrodecomp(int s)
{
	sz=0; dfssize(s,s); fndctr(s,s);
	int cent=ctr;
	dfsctr(cent,cent); br=0; vc[cent]=true; fas=false;
	vi[cent]=true; dodajboju(c[cent]);
	while(!fas && !q.empty())
	{
		int u=q.front();
		dizanje(u);
		q.pop();
	}
	while(!q.empty()) q.pop();
	if(!fas) rez=min(rez,br);
	for(int i=0;i<g[cent].size();i++) if(!vc[g[cent][i]]) centrodecomp(g[cent][i]);
}
int main()
{
	scanf("%d%d",&n,&k);
	for(int i=0;i<n-1;i++)
	{
		int t1,t2;
		scanf("%d%d",&t1,&t2);
		g[t1].push_back(t2);
		g[t2].push_back(t1);
	}
	for(int i=1;i<=n;i++) scanf("%d",&c[i]);
	for(int i=1;i<=n;i++) b[c[i]].push_back(i);
	centrodecomp(1);
	printf("%d",rez-1);
}

Compilation message (stderr)

capital_city.cpp: In function 'void dfssize(int, int)':
capital_city.cpp:11:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[s].size();i++) if(g[s][i]!=f && !vc[g[s][i]]) dfssize(g[s][i],s);
              ~^~~~~~~~~~~~
capital_city.cpp: In function 'int fndctr(int, int)':
capital_city.cpp:17:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[s].size();i++)  if(g[s][i]!=f && !vc[g[s][i]])
              ~^~~~~~~~~~~~
capital_city.cpp: In function 'void dfsctr(int, int)':
capital_city.cpp:31:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[s].size();i++) if(g[s][i]!=f && !vc[g[s][i]]) dfsctr(g[s][i],s);
              ~^~~~~~~~~~~~
capital_city.cpp: In function 'void dodajboju(int)':
capital_city.cpp:36:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(ccnt[co]!=b[co].size()) {fas=true; return;}
     ~~~~~~~~^~~~~~~~~~~~~~
capital_city.cpp:38:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<b[co].size();i++) q.push(b[co][i]);
              ~^~~~~~~~~~~~~
capital_city.cpp: In function 'void centrodecomp(int)':
capital_city.cpp:61:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[cent].size();i++) if(!vc[g[cent][i]]) centrodecomp(g[cent][i]);
              ~^~~~~~~~~~~~~~~
capital_city.cpp: In function 'int main()':
capital_city.cpp:65:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&k);
  ~~~~~^~~~~~~~~~~~~~
capital_city.cpp:69:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&t1,&t2);
   ~~~~~^~~~~~~~~~~~~~~~
capital_city.cpp:73:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=n;i++) scanf("%d",&c[i]);
                        ~~~~~^~~~~~~~~~~~

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