Palindrome檢查數組

Question

我被困在如何使用MASM檢查迴文。

#include <iostream> 
#include <cstring> 
#include<string> 
#include <algorithm> 
using namespace std; 

extern "C" 
char test(char*, int); 


int main() 
{ 
char arr[] = {NULL}; 


cout << "Enter a string: " << endl; 
cin >> arr; 



int name = strlen(arr); 
test(arr, name); 
if (name == 1) 
{ 
    cout << "It is a palindrome! " << endl; 

} 
else 
    cout << "Not a palindrome. " << endl; 

return 0; 
    } 

我問用戶一個字符串，並將其插入到一個數組。我將它發送到程序集文件，如果它爲真，它將返回'1'或者如果爲假，則返回'0'。

.686 
.model flat 

.code 


_test PROC ;named _test because C automatically prepends an underscode, it is needed to interoperate 
push ebp 
mov ebp,esp ;stack pointer to ebp 

mov eax,[ebp+8] 
mov ecx,[ebp+12] 
mov ebp,0 
mov edi,0 
mov edx,0 



loopMe: 
cmp ebp,ecx 
je True 

mov al,[eax+edi] 
mov bl,[edx+esi] 
cmp al,bl ;compare 
jne false ;if not equal then jump to false 
inc edi  
dec esi 
jmp loopMe 

True: 
mov eax,1 
jmp allDone 

False: 
mov eax,0 
jmp allDone 


allDone:  
pop ebp 
ret 
_test ENDP 

END 

當我進入它似乎總是返回0。我檢查了調試器，它會一直跳到即使值相等的假標籤的字符串

。任何幫助表示讚賞。

Answer 1

你是C++使用字符串。

更換

char arr[] = {NULL}; // by the way NULL here has no sence. 

通過

std::string arr; 

和字符串的使用方法做你想做什麼：

• http://www.cplusplus.com/reference/string/string/c_str/
• http://www.cplusplus.com/reference/string/string/size/

Answer 2

所以我最終改變了一下代碼，並得到它的工作。

int main() 
{ 
char arr[32] = {NULL}; 


cout << "Enter a string: " << endl; 
cin >> arr; 



int name = strlen(arr); 
int palindrome= test(arr, name); 

if (palindrome) 
{ 
    cout << "It is a palindrome! " << endl; 

} 
else 
    cout << "Not a palindrome. " << endl; 

return 0; 
} 

然後爲ASM文件

.686 
.model flat 

.code 


_test PROC ;named _test because C automatically prepends an underscode, it is needed to interoperate 
push ebp 
mov ebp,esp ;stack pointer to ebp 

mov ebx,[ebp+8] 
mov ecx,[ebp+12] 
mov edx,ebx 
add edx,ecx 
dec edx 




loopMe: 
cmp ebx,edx 
jge True 

mov ch,[ebx] 
mov cl,[edx] 
cmp ch,cl ;compare 
jne false ;if not equal then jump to false 
inc ebx  
dec edx 
jmp loopMe 

True: 
mov eax,1 
jmp allDone 

False: 
mov eax,0 
jmp allDone 


allDone:  
pop ebp 
ret 
_test ENDP 

END 

我唯一的問題是現在，如果我輸入媽媽的媽媽，而不是它會說，它不是一個迴文。我只需要弄清楚如何在程序集中忽略個案。