Assembly 如何在asm中反转三角形
我一辈子也弄不明白这件事。当我运行这个程序时,前两个三角形输出正确,但是第三个三角形有问题。 我想得到的是:Assembly 如何在asm中反转三角形,assembly,x86,Assembly,X86,我一辈子也弄不明白这件事。当我运行这个程序时,前两个三角形输出正确,但是第三个三角形有问题。 我想得到的是: * * * * * * 但我似乎无法获得所需的正确数量的空间,我一直在一个无限循环中结束 org 100h .data Input db "Enter size of the triangle between 2 to 9: $" ;String to prompt the user Size dw ? ; variable to hold
*
* *
* * *
但我似乎无法获得所需的正确数量的空间,我一直在一个无限循环中结束
org 100h
.data
Input db "Enter size of the triangle between 2 to 9: $" ;String to prompt the user
Size dw ? ; variable to hold size of triangle
spot db " $" ; a space
.code
Main proc
Start:
Mov ah, 09h ; function to display string
Mov dx, offset input ;prompts user for input
int 21h ;interrupt processor to call OS
mov ah, 01h ; DOG get character function #
int 21h; takes user input
sub al, '0' ; subtract ascii value of character zero
mov ah, 0 ;blank top half of ax reigster
mov size, ax ; we use ax instead of al because we used dw instead of db
mov cx, ax ; copy size into variable size and cx reigster
mov bx, 1
call newline
lines: ; outer loop for number of lines
push cx
mov cx,bx
stars: ; inner loop to print stars
mov ah, 02h
mov dl, '*'
int 21h
loop stars
inc bx
call newline
pop cx ; get outer loop value back
loop lines
call newline
; second triangle
mov cx, size
dec bx
lines2:
push cx
mov cx,bx
stars2:
mov ah, 02h
mov dl, '*'
int 21h
loop stars2
dec bx
call newline
pop cx
loop lines2
;end
call newline
; third triangle
mov cx, size
inc bx
lines3:
push cx
mov cx,bx
spaces:
mov ah, 09h
mov dx, offset spot
int 21h
stars3:
mov ah, 02h
mov dl, '*'
int 21h
loop stars3
loop spaces
inc bx
call newline
pop cx
loop lines3
;end
main endp
proc newline
mov ah, 02h ; go to a new line after input
mov dl, 13
int 21h
mov dl, 10
int 21h
ret ;returns back
newline endp
end main
<>你的跳跃和循环没有正确的顺序,空白空间需要自己的计数器,所以我固定了第三个三角形部分:
lines3:
mov bp, size ;<====== BP USED AS BLANK SPACE COUNTER.
sub bp, bx ;<====== MINUS ASTERISK COUNTER.
jz no_spaces ;<====== IF BP IS ZERO, SKIP SPACES.
spaces:
mov ah, 09h
mov dx, offset spot
int 21h
dec bp ;<======= DECREASE COUNTER.
jnz spaces ;<======= IF COUNTER NOT ZERO, REPEAT.
no_spaces:
push cx
mov cx,bx
stars3:
mov ah, 02h
mov dl, '*'
int 21h
loop stars3
call newline
inc bx
pop cx
loop lines3
;end
行3:
mov-bp,大小;和我一起走过这个。当您点击第二个三角形时,size
和bx中的值是什么?如果输入3,那么大小应该是3,ebx也应该是3(对吗?)。您要做的第一件事是dec bx
(2)。然后打印bx星星。然后你dec bx
(1)并循环打印第二行星星。您可以打印bx星和dec bx
(0),然后循环打印第三行星。但是既然bx是零,那么您要打印多少个星星(记住,循环
递减cx,然后检查0)?使用调试器遍历此文件可能会使其更清晰。