题解

#include<bits/stdc++.h>
using namespace std;
void asd(int n,char A,char B,char C){
if(n1)
{
cout<<A<<" -> "<<C<<endl;
}
if(n2)
{
cout<<A<<" -> "<<B<<endl;
cout<<A<<" -> "<<C<<endl;
cout<<B<<" -> "<<C<<endl;
}
if(n>2)
{
asd(n-1,A,C,B);
cout<<A<<" -> "<<C<<endl;
asd(n-1,B,A,C);
}
}
int main(){
int n;
cin>>n;
asd(n,'A','B','C');
return 0;
}