1 #include
     
       2 #include
      
        3  4 typedef char ElemType; 5  6 typedef struct node{ 7     ElemType data; 8     struct node *lson; 9     struct node *rson;10 }Bynode,*Bytree;11 12 Bytree CreateBytree()//树的建立13 {14     char ch;15     Bytree t;16     ch = getchar(); 17     if ( ch == '1')18         t = NULL;19     else 20     { 21         t = (Bytree)malloc(sizeof(Bynode));22         t->data = ch;23         t->lson = CreateBytree();24         t->rson = CreateBytree();25      }26     return t;27 }28 29 void pre(Bytree t)//先序遍历30 {31     if(t)32     {33         putchar(t->data);34         pre(t->lson);35         pre(t->rson);36     }37 }38 39 void in(Bytree t)//中序遍历40 {41     if(t)42     {43         in(t->lson);44         putchar(t->data);45         in(t->rson);46     }47 }48 49 void post(Bytree t)//后序遍历50 {51     if(t)52     {53         post(t->lson);54         post(t->rson);55         putchar(t->data);56     }57 }58 59 void main()60 {61     Bytree t;62     t=CreateBytree();63     printf("先序遍历：");64     pre(t);65     putchar('\n');66     printf("中序遍历：");67     in(t);68     putchar('\n');69     printf("后续遍历：");70     post(t);71     putchar('\n');72 }