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：
正常的：
按ESC退出：
