Submission #363896

#	Time	Username	Problem	Language	Result	Execution time	Memory
363896		ogibogi2004	Shell (info1cup18_shell)	C++14	100 / 100	818 ms	48816 KiB

shell

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int MAXN=1e6+6;
const ll mod=1e9+7;
int n,m,p;
vector<int>g[MAXN];
vector<int>t;
bool vis[MAXN];
void dfs(int u)
{
	vis[u]=1;
	for(auto v:g[u])
	{
		if(vis[v]==0)
		{
			dfs(v);
		}
	}
	t.push_back(u);
}
int a[MAXN];
int where[MAXN];
int w1[MAXN];
ll dp[MAXN];
int main()
{
	cin>>n>>m>>p;
	for(int i=1;i<=p;i++)
	{
		cin>>a[i];
	}
	for(int i=0;i<m;i++)
	{
		int x,y;
		cin>>x>>y;
		g[x].push_back(y);
	}
	for(int i=1;i<=n;i++)
	{
		if(vis[i]==0)
		{
			dfs(i);
		}
	}
	reverse(t.begin(),t.end());
	for(int i=0;i<t.size();i++)where[t[i]]=i;
	/*for(int i=2;i<=p;i++)
	{
		if(where[i-1]>where[i])
		{
			cout<<"0\n";
			return 0;
		}
	}*/
	ll ans=1;
	dp[1]=1ll;
	//cout<<a[1]<<" "<<where[a[1]]<<endl;
	for(int j=where[1];j<=where[a[1]];j++)
	{
		for(auto v:g[t[j]])
		{
			if(where[v]>where[a[1]])continue;
			//cout<<t[j]<<"->"<<v<<endl;
			dp[v]+=dp[t[j]];
			dp[v]%=mod;
		}
	}
	ans*=dp[a[1]];
	//cout<<ans<<endl;
	for(ll i=2;i<=p;i++)
	{
		dp[a[i-1]]=1;
		for(int j=where[a[i-1]];j<=where[a[i]];j++)
		{
			for(auto v:g[t[j]])
			{
				if(where[v]>where[a[i]])continue;
				dp[v]+=dp[t[j]];
				dp[v]%=mod;
			}
		}
		ans*=dp[a[i]];
		ans%=mod;
		//cout<<ans<<endl;
	}
	dp[a[p]]=1;
	for(int j=where[a[p]];j<=where[n];j++)
	{
		for(auto v:g[t[j]])
		{
			if(where[v]>where[n])continue;
			dp[v]+=dp[t[j]];
			dp[v]%=mod;
		}
	}
	ans*=dp[n];
	ans%=mod;
	cout<<ans<<endl;
return 0;
}
/*
6 9 3
3 5 6
1 3
1 3
1 2
2 3
2 4
3 4
3 5
4 5
5 6
*/

Compilation message (stderr)

shell.cpp: In function 'int main()':
shell.cpp:47:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |  for(int i=0;i<t.size();i++)where[t[i]]=i;
      |              ~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 45 / 45
• Subtask 3: 20 / 20
• Subtask 4: 25 / 25