Question

我对低级编程非常陌生并且使用带有4个寄存器的16位，但是我试图编写一个程序来检查是否从键盘输入了一个字符串，并以完整的方式终止停止（。），是一个回文。它输出＆＃39; y＆＃39;如果它是vdu和＆＃39; n＆＃39;如果不。然而，我遇到问题似乎只是在输出＆＃39; y，无论是否是回文

mov bl,70        ; Memory Start Address
mov dl,0         ; how many characters make up the string

loop:
in 00            ;read input from the keyboard
cmp al, 2E       ;check to see if the input is a fullstop
jz palin         ;jump to see if the input is a palindrome
mov [bl], al     ;save the input in memory address
inc bl           ;goto next memory addr in bl
inc dl           ;increment dl by 1 to the length of the string
push al
jmp loop

palin:
cmp dl,0         ;check if it has gone through the whole string
jz ispalin       ;jump it has then the string is a palindrome
mov bl, 70       ;bring back the first input character
mov dl,[bl]
pop cl           ;put the last input character
cmp cl,dl        ;check if these two values are the same
jnz notpalin     ;if they are not then jump to notpalin
inc bl           ;go to the next input addr
dec dl           ;take away 1 from the length of the string
jmp palin        ;jump pack to the start of palin

notpalin:
mov dl,c0
mov cl,6E
mov [dl],cl      ;print the character 'n' to the vdu

ispalin:
mov dl,c0
mov cl,79
mov [dl],cl      ;print the character 'y' to the vdu

end

Answer 1

如果要在代码中的某个位置更改程序流，则需要使用跳转：

notpalin:
mov dl,c0
mov cl,6E
mov [dl],cl      ;print the character 'n' to the vdu
jmp done         ; do not execute the code at ispalin

ispalin:
mov dl,c0
mov cl,79
mov [dl],cl      ;print the character 'y' to the vdu

done:

我没有检查您的其余代码，因此可能还有其他问题。

Asm计划检查回文

1 个答案: