Assembly 协助回文汇编
这就是我目前正在处理的问题Assembly 协助回文汇编,assembly,x86,nasm,Assembly,X86,Nasm,这就是我目前正在处理的问题 .DATA LF EQU 10 String_prompt DB "Enter a character string: ",0 Is_palindrome DB "The string is a palindrome.",0 Not_palindrome DB "The string is not a palindrome.",0 .UDATA user
.DATA
LF EQU 10
String_prompt DB "Enter a character string: ",0
Is_palindrome DB "The string is a palindrome.",0
Not_palindrome DB "The string is not a palindrome.",0
.UDATA
user_input resb 80
strip_input resb 80
.CODE
.STARTUP
; Set up ES register
mov AX, DS
mov ES, AX
try_again:
GetStr user_input
cmp user_input, LF
je try_again
mov EDX, user_input
call string_convert
.EXIT
;********************************************
; string_convert: Eliminate blanks and
; punctuation. Convert to upper case
;
;********************************************
string_convert:
enter 0, 0
xor EBX, EBX
mov ECX, 80
read:
mov AL, [EDX+EBX]
cmp AL, '0'
jl skip
cmp AL, '9'
jg check
check:
sub AL, 20H
cmp AL, 'A'
jl skip
cmp AL, 'Z'
jle write
cmp AL, 5BH :check for ASCII past 'Z'
jge skip
skip:
inc EBX
jmp read
write:
push AX
push ECX
les EDI, user_input
mov ECX, 80
cld
mov AL, 0
repne scasb
leave
ret
strip\u input用户输入的所有标点符号和数字，同时将所有字符转换为大写。我想我的支票安排得很好，但我仍停留在写：LF EQU 10
String_prompt DB "Enter a character string: ",0
Is_palindrome DB "The string is a palindrome.",0
Not_palindrome DB "The string is not a palindrome.",0
index DB 0
.UDATA
user_input resb 80
strip_input resb 80
final_input resb 80
.CODE
.STARTUP
; Set up ES register
mov AX, DS
mov ES, AX
try_again:
PutStr String_prompt
GetStr user_input
cmp word[user_input], LF
je try_again
call string_convert
call string_reverse
call palindrome_check
PutStr user_input
PutStr strip_input
PutStr final_input
cmp EAX, 1
jne notP
PutStr Is_palindrome
notP:
PutStr Not_palindrome
.EXIT
;********************************************
; string_convert: Eliminate blanks and
; punctuation. Convert to upper case
;
;********************************************
string_convert:
enter 0, 0
xor EBX, EBX
mov ECX, 80
read:
cmp ECX, 0
jz endread
mov AL, byte [user_input+EBX]
cmp AL, '9'
jle skip
cmp AL, 7BH
jge skip
check:
inc EBX
or AL, 20H
cmp AL, 'a'
jl skip
cmp AL, 'z'
jle write
skip:
inc EBX
loop read
write:
;PutCh AL
push EBX
mov EBX, [index]
mov byte [strip_input+EBX], AL
inc EBX
mov [index], EBX
pop EBX
loop read
endread:
leave
ret
;*********************************************
; string_reverse: Recursive procedure to
; reverse string
;
;
;*********************************************
string_reverse:
enter 0,0
xor EBX, EBX
xor EAX, EAX
push 0
checknull:
mov AL, byte [strip_input+EBX]
PutCh AL
cmp AL, 0
je reverse
ret
pushtostack:
push AX
inc EBX
call checknull
reverse:
xor EBX, EBX
pop AX
cmp AL, 0
je end
mov byte [final_input+EBX],AL
inc EBX
jmp reverse
end:
leave
ret
;************************************************
;palindrome check: Check for palindrome
;
;************************************************
palindrome_check:
enter 0,0
push ECX
push EDI
push ESI
push DS
push ES
les EDI, [strip_input]
mov EDX, 80
lds ESI, [final_input]
cld
repe cmpsb
je same
xor EAX, EAX
same:
mov EAX, 1
leave
ret
string_reverse:
enter 0,0
xor EBX, EBX
xor EAX, EAX
xor ECX, ECX
push 00h
checknull:
mov AL, byte [strip_input+EBX]
PutLInt EBX
inc EBX
PutCh AL
cmp AL, 00h
jne pushtostack
ret
pushtostack:
push AX
PutLInt EBX
;inc EBX
call checknull
reverse:
pop AX
cmp AL, 00h
je end
mov byte [final_input+ECX],AL
inc ECX
jmp SHORT reverse
end:
leave
ret
strip\u输入完成循环，它就会崩溃，我想它涉及到ret
，它通过反向：
现在我唯一的问题是比较两个字符串strip\u input
和final\u input
我真的不知道该怎么做，有人能帮我吗？为什么要反转字符串？获取您的输入，对其进行清理（删除无效字符），转换为大写或小写，然后获取第一个字节并与最后一个字节进行比较，增加正向索引并减少反向索引，然后再次进行比较，直到两个索引相等为止（字符串中间）。我们必须使用这种特定格式才能获得全额积分