#include<bits/stdc++.h> using namespace std; typedef struct Found{ char ai; Found *Lcheck; Found *Rcheck; }Tree; void check(Tree &T){ char x; cin>>x; if(x==''){ T=NULL; return; } else{ T=new Found; T->ai=x; check(T->Lcheck); check(T->Rcheck); return ; } } void print(Tree &T){ if(T){ cout<ai<<" "; print(T->Lcheck); print(T->Rcheck); return ; } } void printt(Tree &T){ if(T){ printt(T->Lcheck); printt(T->Rcheck); cout<ai<<" "; } } void printtt(Tree &T){ if(T){ printtt(T->Lcheck); cout<ai<<" "; printtt(T->Rcheck); } } bool kong(Tree &T){ if(TNULL){ cout<<"空"<<endl; return true; } else{ cout<<"不空"<<endl; return false; } } int count(Tree &T){ if(TNULL){ return 0; } else if(T->LcheckNULL&&T->RcheckNULL){ return 1; } else{ return count(T->Lcheck)+count(T->Rcheck)+1; } } int high(Tree &T){ if(T==NULL){ return 0; } else{ int l=high(T->Lcheck); int r=high(T->Rcheck); return max(l,r)+1; } } int main(){ Tree T; check(T); cout<<"前序："; print(T); cout<<endl<<"后序："; printt(T); cout<<endl<<"中序："; printtt(T); cout<<endl; kong(T); cout<<endl<<count(T); cout<<endl<<high(T); }