lxshu.asm

用汇编语言编写的二叉树排列算法

dseg segment         
	 mess  db   ' tree is empty!',0Dh,0Ah,"$"
	 ecs    db  64   DUP(?)
	 jsq     dw      1   DUP(0)
	 zh      dw      1   DUP(0)
dseg  ends 
cseg  segment
          assume cs:cseg,ds:dseg
start: mov ax,dseg
	   mov ds,ax
	   mov di,offset ecs
jsl:	   mov ah,01h    ;建树
	   int 21h
	   cmp al,3dh
	   je bls	   
	   mov zh,di
	   mov byte ptr [di], al
	   inc  zh
	   mov di,zh
	   jmp jsl
     bls: mov dl,0dh;开始遍历
           mov ah,2
           int 21h
	   mov dl,0ah
	   mov ah,2
	   int 21h
           mov di,offset ecs;得到树的根结点
	   mov si,di
	   dec si
	   cmp byte ptr [di],00h;树为空
	   je ks 
	   cmp byte ptr [di],20h;结点为空格
	   je ks
pre:     cmp byte ptr [di],00h;前序
           je pre2
	   cmp byte ptr [di],20h	    
	   je pre2
	   jne pre1
ks:       mov dx,offset mess;空树提示信息
            mov ah,9
	    int 21h
	    jmp over
pre1:	   mov zh, di
           mov dl,byte ptr [di]
           mov ah,02h
	   int 21h
	   mov cl,byte ptr [zh]
	   push  cx
	   inc jsq
	   sub zh,si
	   shl zh,1
	   add zh,si
	   mov di,zh
	   jmp pre
pre2:   cmp jsq,0
           je preover;前序遍历完，开始中序遍历
	   pop di
	   dec jsq
           sub di,si
	   shl di,1
	   add di,si
	   inc di
	   jmp pre
preover:   mov dl,0dh;换行
           mov ah,2
           int 21h
	   mov dl,0ah
	   mov ah,2
	   int 21h
           mov di,offset ecs
	   mov si,di
	   dec si
	   mov zh,di
mid :   cmp byte ptr [di],00h;中序
	   je mid2
	   cmp byte ptr [di],20h
           je mid2
mid1 :   mov cx,di
           push cx
	   inc jsq
           sub di,si
	   shl di,1
	   add di,si
	   jmp mid
ks1:     jmp ks
mid2:   cmp jsq,0
           je midover
	   pop di 
	   dec jsq
	   mov dl,byte ptr [di]
	   mov ah,02h
	   int 21h
           sub di,si
	   shl di,1
	   add di,si
	   inc di
	   jmp mid
midover: mov dl,0dh;换行
           mov ah,2
           int 21h
	   mov dl,0ah
	   mov ah,2
	   int 21h
           mov di,offset ecs
           mov si,di
	   dec si
	   mov zh,di	   
aff :   cmp byte ptr [di],00h;后序
	   je aff2
	   cmp byte ptr [di],20h
           je aff2
aff1:   mov cx,di
	   push cx
	   inc jsq
	   sub di,si
	   shl di,1
	   add di,si
	   jmp aff
aff2 : cmp jsq,0
           je over
	   pop di
	   push di
	   sub di,si
	   shl di,1
	   add di,si
	   inc di
	   cmp byte ptr [di],20h
	   je ok
	   cmp byte ptr [di],00h
	   jne aff
ok:	   pop di
	   dec jsq
	   mov dl,byte ptr [di]
	   mov ah,2
	   int 21h
	   mov byte ptr [di],00h
	   cmp jsq,0
	   je over
	   pop di
	   dec jsq
	   jmp aff
over :   mov ah,4ch
           int 21h
cseg ends
        end start