8.1.2前根遍历.txt

来自「MCS51 单片机源码系列之 第八章 树和图 」· 文本 代码 · 共 90 行

STACK	EQU	1FH			
BOTTOM	EQU	00H				
TOP		DATA	3EH			
TREE	EQU		20H			
OUT	EQU	21H					
TST:	
MOV	SP,#5FH				
MOV	DPTR,#DATS			 
MOV	P2,#TREE
MOV	R0,#0
MOV	R2,#32
CPY:	
CLR		A					
MOVC	A,@A+DPTR
MOVX	@R0,A
INC		DPTR
INC		R0
DJNZ	R2,CPY
MOV	DPH,#OUT			
MOV	DPL,#0
MOV	R2,#0
CLR		A
CLEAR:	
MOVX	@DPTR,A				
INC		DPTR
DJNZ	R2,CLEAR
MOV	P2,#TREE			
MOV	R0,#0
MOV	DPH,#OUT			
MOV	DPL,#0
MOVX	A,@R0				
MOVX	@DPTR,A				
INC		R0					
INC		DPTR			
JZ		STOP				
LCALL	SETNULL				
LCALL	PRE					
DATS:	
DB		0BH,41H,42H,43H
DB		44H,45H,46H,00H
DB		47H,48H,49H,00H
DB		4AH,4BH,00H,00H
DB		0,0,0,0
DB		0,0,0,0
DB		0,0,0,0
DB		0,0,0,0
PRE:	
MOVX	A,@R0			
JZ		PREND				
MOVX	@DPTR,A				
INC		DPTR			
MOV	A,R0					
JB		ACC.7,PREND			
LCALL	DPUSH				
CLR		C					
RLC		A
MOV	R0,A					
LCALL	PRE				
LCALL	DPOP				
SETB	C					
RLC		A
MOV	R0,A					
LCALL	PRE					
PREND:	
RET						
SETNULL:
MOV	A,#BOTTOM			
MOV	TOP,A				
RET							
DPUSH:	
INC	TOP						
PUSH	DPH
PUSH	DPL
MOV	DPH,#STACK			
MOV	DPL,TOP			
MOVX	@DPTR,A			
POP		DPL
POP		DPH
RET						
DPOP:	
PUSH	DPH
PUSH	DPL
MOV	DPH,#STACK			
MOV	DPL,TOP				
MOVX	A,@DPTR				
DEC		TOP					
POP		DPL
POP		DPH
RET