Submission #171597

#	Time	Username	Problem	Language	Result	Execution time	Memory
171597		MvC	007 (CEOI14_007)	C++11	30 / 100	329 ms	17484 KiB

007

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define mkp make_pair
#define in insert
#define er erase
#define fd find
#define fr first
#define sc second
typedef long long ll;
typedef long double ld;
const ll INF=0x3f3f3f3f3f3f3f3f;
const ll llinf=(1LL<<62);
const int inf=(1<<30);
const int nmax=2e5+50;
const int mod=1e9+7;
using namespace std;
int n,m,s[2],a[2],d[2][nmax],x,y,mn,i,j;
vector<int>g[nmax];
queue<pair<int,int> >q;
pair<int,int>p;
int main()
{
	//freopen("sol.in","r",stdin);
	//freopen("sol.out","w",stdout);
	//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
	ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
	cin>>n>>m;
	cin>>s[0]>>s[1]>>a[0]>>a[1];
	while(m--)
	{
		cin>>x>>y;
		g[x].pb(y);
		g[y].pb(x);
	}
	for(j=0;j<2;j++)
	{
		for(i=1;i<=n;i++)d[j][i]=inf;
		q.push(mkp(s[j],0));
		d[j][s[j]]=0;
		while(!q.empty())
		{
			p=q.front();
			q.pop();
			for(i=0;i<(int)g[p.fr].size();i++)
			{
				x=g[p.fr][i];
				if(d[j][x]!=inf)continue;
				d[j][x]=p.sc+1;
				q.push(mkp(x,d[j][x]));
			}
		}
	}
	mn=inf;
	for(i=0;i<2;i++)
	{
		x=a[i];
		mn=min(mn,d[1][x]-d[0][x]);
	}
	if(mn<-1)mn=-1;
	if(mn!=-1 && d[0][a[0]]==d[0][a[1]] && d[1][a[0]]==d[1][a[1]])mn--;
	cout<<mn<<endl;
	return 0;
}

• Subtask 1: 9 / 30
• Subtask 2: 21 / 70