040630418.asm

设有一个数组存放学生的成绩

     ;4.30.asm
        .model small
        .stack 
        .data
string  db 5 dup(30h)                          ;存储每个分数段学生的数量
string1 db 'Please enter a number:',0dh,0ah,'$'
string2 db 'Please enter scores:',0dh,0ah,'$'
string3 db 'You have entered a wrong score!',0dh,0ah,'$'
string4 db 'Here are the result:',0dh,0ah,'$'
string5 db 0dh,0ah,'                           ','$'
string6 db 0dh,0ah,'                                ','$'
string7 db 0dh,0ah,'                                     ','$'
score   db 50 dup('$')

        .code
        .startup
        mov  si,offset score
        mov  di,offset string
        mov  bh,00h
        mov  ah,09h
        mov  dx,offset string5
        int  21h
        mov  dx,offset string1
        int  21h
        mov  dx,offset string7
        int  21h
        call read                              ;设置输入的数的个数cx
        mov  cx,ax
        mov  ah,02h
        mov  dl,0ah
        int  21h
        mov  ah,09h
        mov  dx,offset string5
        int  21h
        mov  dx,offset string2
        int  21h
        mov  dx,offset string5
        int  21h
         
again:  cmp  cx,00h         
        jz   final
        call read       ;调用子程序read
        push ax
        push dx
        mov  ah,02h
        mov  dx,' '
        int  21h
        pop  dx
        pop  ax
        cmp  ax,'-'
        jz   next 
        cmp  ax,0       ;判断输入数的范围，如果小于0或者大于100，将显示出错信息，并重新输入(即调用next)
        jb   next
        cmp  ax,100
        ja   next
        call count      ;调用count，返回该数字所在区域，以01h、02h等返回
        cmp  dl,01h
        jz   score1
        cmp  dl,02h
        jz   score2
        cmp  dl,03h
        jz   score3
        cmp  dl,04h
        jz   score4
        cmp  dl,05h
        jz   score5
next:   push dx
        push ax
        mov  ah,09h
        mov  dx,offset string5
        int  21h
        mov  dx,offset string3
        int  21h
        mov  dx,offset string5
        int  21h
        pop  ax
        pop  dx
        jmp  again        
        
score1: add [di],01h         ;为相应的内存的数加1，并储存该数字
        mov [si],al
        inc si
        dec cx
        jmp again 
score2: add [di+01h],01h
        mov [si],al
        inc si
        dec cx
        jmp again
score3: add [di+02h],01h
        mov [si],al
        inc si
        dec cx
        jmp again
score4: add [di+03h],01h
        mov [si],al
        inc si
        dec cx
        jmp again
score5: add [di+04h],01h
        mov [si],al
        inc si
        dec cx
        jmp again
        
final:  xor cx,cx                   
        mov di,offset string
        mov ah,02h
        mov dl,0dh
        int 21h
        mov dl,0ah
        int 21h
        mov ah,09h
        mov dx,offset string5
        int 21h
        mov dx,offset string4       ;说明将输出结果
        int 21h
        mov  dx,offset string6
        int  21h
        mov ah,02h
        mov dl,'E'
        int 21h
        mov dl,' '
        int 21h
        mov dl,'D'
        int 21h
        mov dl,' '
        int 21h
        mov dl,'C'
        int 21h
        mov dl,' '
        int 21h
        mov dl,'B'
        int 21h
        mov dl,' '
        int 21h
        mov dl,'A'
        int 21h
        mov dl,0dh
        int 21h
        mov dl,0ah
        int 21h
        mov ah,09h
        mov dx,offset string6
        int 21h
go:     mov ah,02h                  ;逐个输出结果
        mov dl,[di]
        int 21h
        mov dl,' '
        int 21h
        inc cx
        inc di
        cmp cx,4
        jbe go
        .exit 0
        ;
read    proc
        push bx
        push cx
        push dx
        xor  bx,bx
        xor  cx,cx
read1:  mov  ah,01h         ;每次读一位，并转化为相应的二进制数，以非0-9的数结束
        int  21h
        cmp  al,'-'
        jz   read3
        cmp  al,'0'         ;判断输入的一位数是否在0-9
        jb   read2
        cmp  al,'9'
        ja   read2
        sub  al,30h
        shl  bx,1
        mov  dx,bx
        shl  bx,1
        shl  bx,1
        add  bx,dx
        
        mov  ah,0
        add  bx,ax
        jmp  read1
                
read2:  mov  ax,bx
        pop  dx
        pop  cx
        pop  bx
        ret
read3:  pop  bx
        pop  cx
        pop  dx
        ret        

read    endp                
        
                
count   proc
        push si
        push di
        cmp  al,59     
        jbe  cs1
        cmp  al,69     
        jbe  cs2
        cmp  al,79
        jbe  cs3
        cmp  al,89
        jbe  cs4
        mov  dl,05h
        pop  di
        pop  si
        ret      
cs1:    mov  dl,01h
        pop  di
        pop  si
        ret
cs2:    mov  dl,02h
        pop  di
        pop  si
        ret
cs3:    mov  dl,03h
        pop  di
        pop  si
        ret
cs4:    mov  dl,04h
        pop  di
        pop  si
        ret
count   endp                
        end