oj.uz

Submission #108869

# Submission time Handle Problem Language Result Execution time Memory
108869 2019-05-02T10:32:05 Z fjzzq2002 Mousetrap (CEOI17_mousetrap) C++14
45 / 100
 1413 ms 67676 KB 
#include <iostream>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
#include <string>
#include <bitset>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <algorithm>
#include <sstream>
#include <stack>
#include <iomanip>
#include <assert.h>
using namespace std;
#define pb push_back
#define mp make_pair
typedef pair<int,int> pii;
typedef long long ll;
typedef double ld;
typedef vector<int> vi;
#define fi first
#define se second
#define fe first
#define FO(x) {freopen(#x".in","r",stdin);freopen(#x".out","w",stdout);}
#define Edg int M=0,fst[SZ],vb[SZ],nxt[SZ];void ad_de(int a,int b){++M;nxt[M]=fst[a];fst[a]=M;vb[M]=b;}void adde(int a,int b){ad_de(a,b);ad_de(b,a);}
#define Edgc int M=0,fst[SZ],vb[SZ],nxt[SZ],vc[SZ];void ad_de(int a,int b,int c){++M;nxt[M]=fst[a];fst[a]=M;vb[M]=b;vc[M]=c;}void adde(int a,int b,int c){ad_de(a,b,c);ad_de(b,a,c);}
#define es(x,e) (int e=fst[x];e;e=nxt[e])
#define esb(x,e,b) (int e=fst[x],b=vb[e];e;e=nxt[e],b=vb[e])
#define SZ 2000555
int n,t,m,fa[SZ],f[SZ]; Edg
vector<int> so[1000555];
void dfs(int x)
{
	for esb(x,e,b)
		if(b!=fa[x]) fa[b]=x,so[x].pb(b),dfs(b);
}
bool sp[SZ];
void dp(int x)
{
	if(x==m)
	{
		f[x]=0;
		return;
	}
	for esb(x,e,b)
		if(b!=fa[x]) dp(b);
	vector<ll> ss;
	ll spp=-8e18;
	for esb(x,e,b)
		if(b!=fa[x])
		{
			if(!sp[b])
				ss.pb(f[b]+1+so[x].size()-2-sp[x]); //???
			else
				ss.pb(f[b]),spp=f[b];
		}
	sort(ss.begin(),ss.end(),greater<ll>());
	if(ss.size()==0) f[x]=0;
	else if(ss.size()==1) f[x]=!sp[x];
	else
	{
		if(ss[0]==ss[1]||ss[0]!=spp)
			f[x]=ss[1]+1;
		else f[x]=spp;
	}
	if(sp[x]) f[x]-=(int)so[x].size()-1;
//	cout<<x<<"w"<<f[x]<<"\n";
}
int main()
{
	scanf("%d%d%d",&n,&m,&t);
	for(int i=1;i<n;++i)
	{
		int a,b;
		scanf("%d%d",&a,&b);
		adde(a,b);
	}
	dfs(t);
	ll ans=0;
	if(t==m)
	{
		puts("0");
		return 0;
	}
	for(int j=m;;j=fa[j])
	{
		sp[j]=1;
		if(j!=m)
			ans+=(int)so[j].size()-1;
		if(j==t) break;
	}
//	cerr<<"CA:"<<ans<<"\n";
	dp(t); ans+=f[t];
	printf("%lld\n",ans);
}

Compilation message

mousetrap.cpp: In function 'int main()':
mousetrap.cpp:75:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d",&n,&m,&t);
  ~~~~~^~~~~~~~~~~~~~~~~~~
mousetrap.cpp:79:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&a,&b);
   ~~~~~^~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 23936 KB Output is correct
2 Correct 22 ms 23808 KB Output is correct
3 Correct 23 ms 23936 KB Output is correct
4 Correct 27 ms 23936 KB Output is correct
5 Correct 23 ms 23800 KB Output is correct
6 Correct 25 ms 23808 KB Output is correct
7 Correct 27 ms 23800 KB Output is correct
8 Correct 25 ms 23864 KB Output is correct
9 Correct 24 ms 23808 KB Output is correct
10 Correct 23 ms 23936 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 431 ms 66852 KB Output is correct
2 Correct 390 ms 62868 KB Output is correct
3 Correct 1369 ms 67596 KB Output is correct
4 Correct 696 ms 45992 KB Output is correct
5 Correct 1413 ms 67676 KB Output is correct
6 Correct 1295 ms 67616 KB Output is correct

Subtask #3
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 23936 KB Output is correct
2 Correct 22 ms 23808 KB Output is correct
3 Correct 23 ms 23936 KB Output is correct
4 Correct 27 ms 23936 KB Output is correct
5 Correct 23 ms 23800 KB Output is correct
6 Correct 25 ms 23808 KB Output is correct
7 Correct 27 ms 23800 KB Output is correct
8 Correct 25 ms 23864 KB Output is correct
9 Correct 24 ms 23808 KB Output is correct
10 Correct 23 ms 23936 KB Output is correct
11 Incorrect 21 ms 23936 KB Output isn't correct
12 Halted 0 ms 0 KB -

Subtask #4
0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 23936 KB Output is correct
2 Correct 22 ms 23808 KB Output is correct
3 Correct 23 ms 23936 KB Output is correct
4 Correct 27 ms 23936 KB Output is correct
5 Correct 23 ms 23800 KB Output is correct
6 Correct 25 ms 23808 KB Output is correct
7 Correct 27 ms 23800 KB Output is correct
8 Correct 25 ms 23864 KB Output is correct
9 Correct 24 ms 23808 KB Output is correct
10 Correct 23 ms 23936 KB Output is correct
11 Correct 431 ms 66852 KB Output is correct
12 Correct 390 ms 62868 KB Output is correct
13 Correct 1369 ms 67596 KB Output is correct
14 Correct 696 ms 45992 KB Output is correct
15 Correct 1413 ms 67676 KB Output is correct
16 Correct 1295 ms 67616 KB Output is correct
17 Incorrect 21 ms 23936 KB Output isn't correct
18 Halted 0 ms 0 KB -