汇编：从键盘录入20个数（-128~127），求最大值

汇编：从键盘录入20个数（-128~127），求最大值

include 一套工具.mac
data segment
	show db "Please Input twenty numbers:$"
	iit1 db "The $"
	iit2 db " number is:$"
	buf db 20 dup(?)
	x   db ?,?,?,?  ;x[0]用来存负号
	w   db ?  ;用于显示提示信息
	max db ?
	boundary db "128$"
	display db "Max:$"
	error1 db "Input error!",13,10,"Please Input again:$"
data ends

stack segment

stack ends

code segment
assume ds:data,cs:code,ss:stack
start:
	mov ax,data
	mov ds,ax
	mov ax,stack
	mov ss,ax
	
	mov bx,0
	push bx
	mov bx,1
			;显示提示输入信息
	oustring show
	ld
inpu1:     ;显示提示输入信息
	oustring iit1
	
	inc w
	cmp w,9
	jg www
	mov dl,w
	add dl,30h
	mov ah,2
	int 21h
	
	oustring iit2
set1:   ;输入
	input
	cmp al,1bh   ;ESC退出
	jz exit
	cmp al,13      ;回车
	jz outpu1
	
	cmp al,'-'
	jz minus
	          ;判断是否在0-9
	cmp al,30h
	jl error0
	cmp al,39h
	jg error0
	
	cmp bx,4
	jg error0
	
	sub al,30h
	mov x[bx],al ;输入的字符合法，从x[1]开始存
	inc bx
	jmp set1

minus:
	cmp x[0],0
	jnz error0    ;负号已存在则输出错误信息
	mov x[0],al  ;把负号存入x[0]中
	jmp set1
	
outpu1:
	cmp bx,1
	jz error0
	cmp x[0],'-'      
	jz negativedealwith

	cmp bx,2
	jz onedigit
	cmp bx,3
	jz twodigit
	
	mov al,x+1
	mov cl,100
	imul cl
	mov bl,al
	mov al,x+2
	mov cl,10
	imul cl
	add al,x+3
	mov bh,0
	cbw
	add ax,bx
	cmp ax,127
	jg error0
	
	pop bx
	mov buf[bx],al
	inc bx
	cmp bx,19
	jg outpu2
	push bx
	;清0
	jmp clear
	
onedigit:
	pop bx
	mov al,x+1
	mov buf[bx],al
	inc bx
	cmp bx,19
	jg outpu2
	push bx
	;清0
	jmp clear
	
twodigit:
	mov al,x+1
	mov cl,10
	imul cl
	add al,x+2
	
	pop bx
	mov buf[bx],al
	inc bx
	cmp bx,19
	jg outpu2
	push bx
	;清0
	jmp clear
	
negativedealwith:
	cmp bx,2
	jz onebit
	cmp bx,3
	jz twobit
	
	mov al,x+1
	mov cl,100
	imul cl
	mov bl,al
	mov al,x+2
	mov cl,10
	imul cl
	add al,x+3
	mov bh,0
	cbw
	neg ax
	neg bx
	add ax,bx
	cmp ax,-128
	jl error0
	
	pop bx
	mov buf[bx],al
	inc bx
	cmp bx,19
	jg outpu2
	push bx
	;清0
	jmp clear
	
onebit:
	mov al,x+1
	neg al
	pop bx
	mov buf[bx],al
	inc bx
	cmp bx,19
	jg outpu2
	push bx
	;清0
	jmp clear

twobit:
	mov al,x+1
	mov cl,10
	imul cl
	add al,x+2
	neg al
	
	pop bx
	mov buf[bx],al
	inc bx
	cmp bx,19
	jg outpu2
	push bx
	;清0
	jmp clear
	
clear:
	;清0操作
	mov bx,0
	mov cx,4
re2:
	mov x[bx],0
	inc bx
	loop re2
	mov bx,1
	ld
	jmp inpu1
	
error0:    ;输入错误
	ld
	oustring error1
	
	;关键的一步，清0操作
	mov bx,0
	mov cx,4
re1:
	mov x[bx],0
	inc bx
	loop re1
	mov bx,1
	jmp set1
	
www:     ;显示提示输入信息
	mov al,w
	cbw
	mov cl,10
	idiv cl
	mov cl,ah
	add al,30h
	output al
	add cl,30h
	output cl
	
	oustring iit2
	jmp set1
	
outpu2:
	ld
	oustring display
	
	mov cx,19
	mov bx,0
	mov al,buf[bx]
set2:
	cmp al,buf[bx+1]
	jl exchange
	inc bx
	loop set2
	jmp outpu3
exchange:
	mov al,buf[bx+1]
	inc bx
	loop set2
outpu3:
	mov max,al
	cmp max,0
	jl minusout
outpu4:
	cmp max,10
	jl oneout1
	cmp max,100
	jl twoout1
	
	mov al,max
	cbw
	mov cl,100
	idiv cl
	mov cl,ah
	add al,30h
	output al
	mov al,cl
	cbw
	mov cl,10
	idiv cl
	mov cl,ah
	add al,30h
	output al
	add cl,30h
	output cl
	jmp exit
	
oneout1:
	add max,30h
	output max
	jmp exit

twoout1:
	mov al,max
	cbw
	mov cl,10
	idiv cl
	mov cl,ah
	mov dl,al
	add dl,30h
	mov ah,2
	int 21h
	add cl,30h
	output cl
	jmp exit
	
minusout:
	output '-'
	cmp max,-128
	jz outpu5
	neg max
	jmp outpu4
	
outpu5:
	oustring boundary
exit:
	mov ah,4ch
	int 21h
code ends
end start

运行结果如下：

1.边界检测：

2.三位数之间的比较检测：

3.两位数之间比较检测：

4.一位数比较检测：

5.综合检测：