递归，但我不太懂

#include<iostream>
using namespace std;
long long n;
string so = "A", dest = "C";
string mid = "B";
void hanoi(long long n, string so, string mid, string dest){
if (n==1){
cout<<so<<" --"<<n<<"--> "<<dest<<endl;
return ;
}
hanoi(n-1, so, dest, mid);
cout<<so<<" --"<<n<<"--> "<<dest<<endl;
hanoi(n-1, mid, so, dest);
}
int main(){
cin>>n;
hanoi(n, so, mid, dest);
return 0;
}
还是不太懂递归的思路