답안 #171523

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
171523	2019-12-28T22:26:23 Z	TadijaSebez	007 (CEOI14_007)	C++11	100 / 100	511 ms	39084 KB

007

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
const int N=200050;
vector<int> E[N];
void BFS(int x, int n, int d[], vector<int> p[])
{
	for(int i=1;i<=n;i++) d[i]=-1;
	queue<int> q;
	q.push(x);
	d[x]=0;
	while(q.size())
	{
		int u=q.front();
		q.pop();
		for(int v:E[u])
		{
			if(d[v]==-1)
			{
				d[v]=d[u]+1;
				q.push(v);
				p[v].pb(u);
			}
			else if(d[v]==d[u]+1) p[v].pb(u);
		}
	}
}
int ds[N],dd[N];
vector<int> ps[N],pd[N];
void DFS(int u, int mark, int w[], vector<int> p[])
{
	w[u]|=mark;
	for(int v:p[u]) if((w[v]&mark)==0) DFS(v,mark,w,p);
}
int sw[N],dw[N];
bool Check(int a, int b, int n)
{
	DFS(a,1,sw,ps);
	DFS(b,2,sw,ps);
	int mns=ds[a];
	for(int i=1;i<=n;i++) if(sw[i]==3) mns=min(mns,ds[a]-ds[i]);
	DFS(a,1,dw,pd);
	DFS(b,2,dw,pd);
	int mnd=dd[a];
	for(int i=1;i<=n;i++) if(dw[i]==3) mnd=min(mnd,dd[a]-dd[i]);
	//printf("%i %i\n",mns,mnd);
	return mns>mnd;
}
int main()
{
	int n,m,s,d,a,b;
	scanf("%i %i",&n,&m);
	scanf("%i %i %i %i",&s,&d,&a,&b);
	for(int i=1,u,v;i<=m;i++) scanf("%i %i",&u,&v),E[u].pb(v),E[v].pb(u);
	BFS(s,n,ds,ps);
	BFS(d,n,dd,pd);
	//printf("%i %i %i %i\n",ds[a],ds[b],dd[a],dd[b]);
	int ans=min(dd[a]-ds[a],dd[b]-ds[b]);
	ans=max(ans,-1);
	if(ans!=-1 && dd[a]==dd[b] && ds[a]==ds[b])
	{
		if(Check(a,b,n)) ans--;
	}
	printf("%i\n",ans);
	return 0;
}

Compilation message

007.cpp: In function 'int main()':
007.cpp:52:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%i %i",&n,&m);
  ~~~~~^~~~~~~~~~~~~~~
007.cpp:53:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%i %i %i %i",&s,&d,&a,&b);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
007.cpp:54:59: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1,u,v;i<=m;i++) scanf("%i %i",&u,&v),E[u].pb(v),E[v].pb(u);
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~

Subtask #1

30.0 / 30.0

#	결과	실행 시간	메모리	Grader output
1	Correct	15 ms	14456 KB	Output is correct
2	Correct	15 ms	14456 KB	Output is correct
3	Correct	15 ms	14284 KB	Output is correct
4	Correct	15 ms	14456 KB	Output is correct
5	Correct	15 ms	14456 KB	Output is correct
6	Correct	15 ms	14456 KB	Output is correct
7	Correct	15 ms	14456 KB	Output is correct
8	Correct	14 ms	14456 KB	Output is correct
9	Correct	15 ms	14456 KB	Output is correct
10	Correct	15 ms	14584 KB	Output is correct
11	Correct	15 ms	14456 KB	Output is correct
12	Correct	15 ms	14456 KB	Output is correct
13	Correct	15 ms	14456 KB	Output is correct
14	Correct	15 ms	14456 KB	Output is correct
15	Correct	15 ms	14456 KB	Output is correct
16	Correct	16 ms	14456 KB	Output is correct
17	Correct	16 ms	14584 KB	Output is correct
18	Correct	15 ms	14584 KB	Output is correct
19	Correct	16 ms	14456 KB	Output is correct
20	Correct	16 ms	14584 KB	Output is correct
21	Correct	15 ms	14588 KB	Output is correct
22	Correct	15 ms	14456 KB	Output is correct
23	Correct	15 ms	14584 KB	Output is correct
24	Correct	16 ms	14588 KB	Output is correct

Subtask #2

70.0 / 70.0

#	결과	실행 시간	메모리	Grader output
1	Correct	54 ms	19320 KB	Output is correct
2	Correct	75 ms	21880 KB	Output is correct
3	Correct	59 ms	19636 KB	Output is correct
4	Correct	108 ms	22248 KB	Output is correct
5	Correct	53 ms	18936 KB	Output is correct
6	Correct	58 ms	19576 KB	Output is correct
7	Correct	69 ms	20344 KB	Output is correct
8	Correct	64 ms	20344 KB	Output is correct
9	Correct	90 ms	21032 KB	Output is correct
10	Correct	267 ms	28948 KB	Output is correct
11	Correct	126 ms	25464 KB	Output is correct
12	Correct	164 ms	27784 KB	Output is correct
13	Correct	132 ms	26024 KB	Output is correct
14	Correct	105 ms	23672 KB	Output is correct
15	Correct	170 ms	28152 KB	Output is correct
16	Correct	168 ms	27768 KB	Output is correct
17	Correct	151 ms	27384 KB	Output is correct
18	Correct	156 ms	27228 KB	Output is correct
19	Correct	219 ms	28128 KB	Output is correct
20	Correct	363 ms	32908 KB	Output is correct
21	Correct	239 ms	33808 KB	Output is correct
22	Correct	214 ms	30584 KB	Output is correct
23	Correct	220 ms	31644 KB	Output is correct
24	Correct	259 ms	33272 KB	Output is correct
25	Correct	225 ms	31608 KB	Output is correct
26	Correct	191 ms	29688 KB	Output is correct
27	Correct	227 ms	32572 KB	Output is correct
28	Correct	235 ms	32376 KB	Output is correct
29	Correct	312 ms	31096 KB	Output is correct
30	Correct	452 ms	34132 KB	Output is correct
31	Correct	272 ms	36276 KB	Output is correct
32	Correct	236 ms	32376 KB	Output is correct
33	Correct	220 ms	31736 KB	Output is correct
34	Correct	270 ms	33912 KB	Output is correct
35	Correct	246 ms	34040 KB	Output is correct
36	Correct	249 ms	34988 KB	Output is correct
37	Correct	291 ms	34672 KB	Output is correct
38	Correct	281 ms	35796 KB	Output is correct
39	Correct	283 ms	35448 KB	Output is correct
40	Correct	393 ms	35832 KB	Output is correct
41	Correct	511 ms	39084 KB	Output is correct