汇编语言：统计学生成绩小程序（增加了边界判断）

淩亂°似流年 2022-05-24 02:57 99阅读 0赞

从键盘录入10个学生成绩（0-100），录入完毕自动统计各分段的学生数。如果录入的不是0-100，则报错并重新输入。而且，按下ESC直接结束程序。之前没有对边界进行判断，结果造成了统计人数超过9以后就不能正常显示了此次加了边界判断，如果人数更大的话以此类推，若超过100则再另行处理。

include 一套工具.mac
    data segment
    	buf db 10 dup(?)
    	w db 3 dup (?)
    	s6 db ?
    	s7 db ?
    	s8 db ?
    	s9 db ?
    	show db "Please input ten scores:$"
    	show1 db "The number of 0-59:$"
    	show2 db "The number of 60-79:$"
    	show3 db "The number of 80-89:$"
    	show4 db "The number of 90-100:$"
    	error1 db "Input error!$"
    data ends
    
    code segment
    	assume cs:code,ds:data
    start:
    	mov ax,data
    	mov ds,ax
    	oustring show
    	mov bx,0
    	mov di,0
    set1:
    	input
    	escexit al
    	ldjudge al
    	cmpzn al
    	and al,0fh
    	cmp bx,2
    	jg error
    	mov w[bx],al
    	inc bx
    	jmp set1
    judge:
    	cmp bx,0
    	jz error
    	cmp bx,1
    	jz onebit
    	cmp bx,2
    	jz twobit
    	cmp w[0],1
    	jnz error
    	threedigit w
    	cmp al,100
    	jg error
    	jmp ret1
    onebit:
    	onedigit w
    	jmp ret1
    twobit:
    	twodigit w
    	jmp ret1
    error:
    	ld
    	oustring error1
    	mov bx,0
    	mov cx,3
    	jmp clear
    ret1:
    	mov buf[di],al
    	inc di
    	cmp di,9
    	jg compare
    	mov bx,0
    	mov cx,3
    clear:
    	mov w[bx],0
    	inc bx
    	loop clear
    	ld
    	oustring show
    	mov bx,0
    	jmp set1
    compare:
    	mov cx,10
    	mov bx,0
    ret2:
    	cmp buf[bx],60
    	jl s1
    	cmp buf[bx],80
    	jl s2
    	cmp buf[bx],90
    	jl s3
    	inc s9
    	jmp s4
    s1:
    	inc s6
    	jmp s4
    s2:
    	inc s7
    	jmp s4
    s3:
    	inc s8
    s4:
    	inc bx
    	loop ret2
    	ld
    	oustring show1
    	cmp s6,10
    	jge s6ab
    	add s6,30h
    	output s6
    ss1:
    	ld
    	oustring show2
    	cmp s7,10
    	jge s7ab
    	add s7,30h
    	output s7
    ss2:
    	ld
    	oustring show3
    	cmp s8,10
    	jge s8ab
    	add s8,30h
    	output s8
    ss3:
    	ld
    	oustring show4
    	cmp s9,10
    	jge s9ab
    	add s9,30h
    	output s9
    	ld
    	jmp exit
    
    s6ab:
    	mov al,s6
    	cbw
    	mov cl,10
    	idiv cl
    	mov bl,ah
    	add al,30h
    	mov dl,al
    	mov ah,2
    	int 21h
    	add bl,30h
    	mov dl,bl
    	int 21h
    	jmp ss1
    s7ab:
    	mov al,s7
    	cbw
    	mov cl,10
    	idiv cl
    	mov bl,ah
    	add al,30h
    	mov dl,al
    	mov ah,2
    	int 21h
    	add bl,30h
    	mov dl,bl
    	int 21h
    	jmp ss2
    s8ab:
    	mov al,s8
    	cbw
    	mov cl,10
    	idiv cl
    	mov bl,ah
    	add al,30h
    	mov dl,al
    	mov ah,2
    	int 21h
    	add bl,30h
    	mov dl,bl
    	int 21h
    	jmp ss3
    s9ab:
    	mov al,s9
    	cbw
    	mov cl,10
    	idiv cl
    	mov bl,ah
    	add al,30h
    	mov dl,al
    	mov ah,2
    	int 21h
    	add bl,30h
    	mov dl,bl
    	int 21h
    	
    exit:
    	mov ah,4ch
    	int 21h
    code ends
    end start

运行结果示意：

先来一个极端的：

![20180523160451327][]

正常的：

![20180519003625966][]

![20180519003635491][]

按ESC退出：

![20180519003651741][]

[20180523160451327]: /images/20220524/9450079e2a8d478f8d2afea9c9a3b3b4.png
[20180519003625966]: /images/20220524/725c88b84b514b5ca800f3ac0881899e.png
[20180519003635491]: /images/20220524/3daf31a6367e4bf3972d159a2445ddf1.png
[20180519003651741]: /images/20220524/998fae0f7e0a4dd1bfd1ca682eb2d758.png