我的c++代码如下:

#include<bits/stdc++.h>
using namespace std;
#define re register

int read(){
	re int x=0,cf=1;
	re char ch=getchar();
	while(!isdigit(ch)){
		if(ch=='-'){
			cf=-1;
		}
		ch=getchar();
	}
	while(isdigit(ch)){
		x=(x<<1)+(x<<3)+(ch^48);
		ch=getchar();
	}
	return x*cf;
}

int const M=20;

struct node{
	int c1;
	int c2;
}ch[M];

int const N=11;
int head[N],nex[M],to[M];
int idx;

void add(int u,int v){
	to[++idx]=v;
	nex[idx]=head[u];
	head[u]=idx;
}

bool mp[N][N];
bool vis[N];
int ce[10000];

string mul(string str1,string str2){
	int len1,len2;
	len1=str1.size();
	len2=str2.size();
	reverse(str1.begin(),str1.end());
	reverse(str2.begin(),str2.end());
	int len=len1+len2;
	for(int i=0;i<len1;i++){
		for(int j=0;j<len2;j++){
			ce[i+j]+=(str1[i]-'0')*(str2[j]-'0');
			ce[i+j+1]+=ce[i+j]/10;
			ce[i+j]%=10;
		}
	}
	while(!ce[len-1]&&len>1) len--;
	string ans="";
	for(int i=0;i<len;i++){
		char now=(char)(ce[i]+'0');
		ans=now+ans;
	}
	return ans;
}

string tur(int x){
	string s="";
	while(x){
		int a=x%10;
		a+=48;
		x/=10;
		s=(char)a+s;
	}
	return s;
}

int main(){
	freopen("generate.in","r",stdin);
	freopen("generate.out","w",stdout);
	string n;
	cin>>n;
	int k=read();
	for(re int i=1;i<=k;++i){
		ch[i].c1=read();
		ch[i].c2=read();
		add(ch[i].c1,ch[i].c2);
	}
	for(re int i=0;i<=9;++i){
		memset(vis,false,sizeof(vis));
		queue<int> q;
		q.push(i);
		vis[i]=true;
		while(!q.empty()){
			int x=q.front();
			q.pop();
			for(re int j=head[x];j;j=nex[j]){
				if(vis[to[j]]) continue;
				vis[to[j]]=true;
				q.push(to[j]);
			}
		}
		for(re int j=0;j<=9;++j){
			mp[i][j]=vis[j];
		}
		mp[i][i]=true;
	}
	int len=n.size();
	string ans="1";
	for(re int i=0;i<len;++i){
		int anan=0;
		int now=n[i]-'0';
		if(i==0){
			for(re int j=1;j<=9;++j){
				if(mp[now][j]) anan++;
			}
			ans=mul(ans,tur(anan));
			continue;
		}
		for(re int j=0;j<=9;++j){
			if(mp[now][j]) anan++;
		}
		anan--;
		ans=mul(ans,tur(anan));
	}
	cout<<ans<<endl;
	return 0;
}
/*
234 2
2 5
3 6
*/