Submission #670313

#	Time	Username	Problem	Language	Result	Execution time	Memory
670313		MilosMilutinovic	Jail (JOI22_jail)	C++14	0 / 100	24 ms	6340 KiB

jail

#include <iostream>
#include <algorithm>
#include<cmath>
#include<cstring>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<iomanip>
#include<ctime>
#include<set>
#include<map>
#include<queue>
#include<stack>
#include<bitset>
#include<cassert>
#define pb push_back
#define mk make_pair
using namespace std;
int n,m,go[120005][22],dep[120005],s[120005],t[120005],dfn[120005],dfo[120005],T;
vector<int> g[120005];
void dfs(int v,int pr)
{
	dep[v]=dep[pr]+1;go[v][0]=pr;dfn[v]=++T;
	for(int u:g[v])if(u!=pr)dfs(u,v);
	dfo[v]=T;
}
int lca(int u,int v)
{
	if(dep[u]<dep[v])swap(u,v);
	for(int i=19;i>=0;i--)if(dep[go[u][i]]>=dep[v])u=go[u][i];
	for(int i=19;i>=0;i--)if(go[u][i]!=go[v][i])u=go[u][i],v=go[v][i];
	return u==v?u:go[u][0];
}
int deg[120005];vector<int> e[120005];
void init()
{
	T=0;
	for(int i=1;i<=n;i++)g[i].clear(),go[i][0]=0;
	for(int i=1;i<=m;i++)deg[i]=0,e[i].clear();
}
void adde(int x,int y){deg[y]++;e[x].pb(y);}
bool in(int x,int y){return dfn[x]<=dfn[y]&&dfo[y]<=dfo[x];}
bool on(int x,int y,int z){int l=lca(x,y);return in(l,z)&&(in(z,y)||in(z,y));}
int qu[505],qsz;
void solve()
{
	init();scanf("%d",&n);
	for(int i=1,u,v;i<n;i++)scanf("%d%d",&u,&v),g[u].pb(v),g[v].pb(u);
	dfs(1,1);
	for(int i=1;i<=n;i++)for(int j=1;j<20;j++)go[i][j]=go[go[i][j-1]][j-1];
	scanf("%d",&m);
	for(int i=1;i<=m;i++)scanf("%d%d",&s[i],&t[i]);
	for(int i=1;i<=m;i++)for(int j=1;j<=m;j++)if(i!=j&&on(s[i],t[i],s[j]))adde(j,i);
	qsz=0;for(int i=1;i<=m;i++)if(deg[i]==0)qu[++qsz]=i;
	for(int i=1;i<=qsz;i++)for(int j:e[qu[i]]){
		deg[j]--;
		if(deg[j]==0)qu[++qsz]=j;
	}
	bool ok=1;for(int i=1;i<=m;i++)ok&=(deg[i]==0);
	printf(ok?"Yes\n":"No\n");
}
int main()
{
	int t;scanf("%d",&t);
	while(t--)solve();
	return 0;
}

Compilation message (stderr)

jail.cpp: In function 'void solve()':
jail.cpp:47:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |  init();scanf("%d",&n);
      |         ~~~~~^~~~~~~~~
jail.cpp:48:31: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |  for(int i=1,u,v;i<n;i++)scanf("%d%d",&u,&v),g[u].pb(v),g[v].pb(u);
      |                          ~~~~~^~~~~~~~~~~~~~
jail.cpp:51:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |  scanf("%d",&m);
      |  ~~~~~^~~~~~~~~
jail.cpp:52:28: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |  for(int i=1;i<=m;i++)scanf("%d%d",&s[i],&t[i]);
      |                       ~~~~~^~~~~~~~~~~~~~~~~~~~
jail.cpp: In function 'int main()':
jail.cpp:64:13: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |  int t;scanf("%d",&t);
      |        ~~~~~^~~~~~~~~

• Subtask 1: 0 / 5
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• Subtask 3: 0 / 16
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