;两个整数是用非压缩型的BCD码存储的
;任意长度的两个数的加法
;输入的非数字字符将被忽略
dseg segment
msg1 db "Please input the first number:",0dh,0ah,"$"
msg2 db "Please input the second number:",0dh,0ah,"$"
remsg db "The reslut is:$"
msg3 db "Any ket to quit$"
b1_len dw 0
buf_1 db 100 dup(0)
b2_len dw 0
buf_2 db 100 dup(0)
dseg ends
;########################################################
cseg segment
assume cs:cseg,ds:dseg
;******************************************
main proc far ;start of the program
mov dx,dseg
mov ds,dx
lea dx,msg1
mov ah,09
int 21h
lea bx,buf_1 ;input the first number
call input
call newline
lea dx,msg2
mov ah,09
int 21h
lea bx,buf_2 ;input the second number
call input
call adder
call newline
lea dx,remsg
mov ah,09
int 21h
lea bx,buf_1
call show
call newline
lea dx,msg3
mov ah,09
int 21h
call ktq ;any Key To Quit
exit:
mov ah,4ch
int 21h
ret
main endp
;******************************
newline proc near ;回车换行
push ds
push dx
push ax
mov dl,0ah
mov ah,02
int 21h
mov dl,0dh
mov ah,02
int 21h
pop ax
pop dx
pop ds
ret
newline endp
;************************
input proc near ;bx:数组首地址,第一个元素方长度
push ds
push ax
push dx
;----------------------------------------
xor si,si ;clear si to zero
inc si
next:
cmp si,100
je over ;over
mov ah,01
int 21h
cmp al," "
je over ;input over
cmp al,0dh
je over
cmp al,"0" ;忽略其他字符
jb next
cmp al,"9"
ja next
sub al,30h ;to 十进制
; 非压缩型BCD码
mov [bx+si],al
inc si
jmp next
over:
dec si
mov word ptr [bx-1],si ;save length
;--------------------------------------
pop dx
pop ax
pop ds
ret
input endp
;******************
show proc near ;bx:数组首地址
push ds
push ax
push dx
;-----------
mov cx,[bx-1] ;length of the array
xor si,si
inc si
nextsh:
mov ah,02
mov dl,byte ptr [bx+si]
add dl,30h ;to ASSII
int 21h
inc si
loop nextsh
;-----------
pop dx
pop ax
pop ds
ret
show endp
;*******************
;未完成
adder proc near ;buf_1,buf_2分别是数组的首地址
;结果放到buf_1数组中
;进位CF
push ds
push ax
push dx
;----------------------------------------------
mov si,word ptr [buf_1-1] ;si存放bx的长度
mov cx,si
mov di,word ptr [buf_2-1] ;di存放bp的长度
xor dl,dl ;clear dl
cmp cx,di
mov word ptr [buf_1-1],cx
jae continue ;cx存放两个数组中较大一个的长度
mov cx,word ptr [buf_2-1]
mov word ptr [buf_1-1],cx ;修改结果的长度
continue:
mov al,dl
xor dl,dl ;clear dl to zero
cmp si,0
je si_z
add al,[buf_1+si]
dec si
jmp L_DI
si_z:
add al,0
L_DI:
cmp di,0
je di_z
add al,byte ptr [buf_2+di]
dec di
aaa
adc dl,0
jmp conti
di_z:
add al,0
aaa
adc dl,0 ;^^^^
conti:
mov bx,cx
mov [buf_1+bx],al
loop continue
;----------------------------------
pop dx
pop ax
pop ds
ret
adder endp
;*******************
ktq proc near
mov ah,08
int 21h
ret
ktq endp
;********************
cseg ends
;###############################################################
end main
