Brother incompetence, begging for prawn guidance (with me learning C ++)

zhanglei88

Digital encryption:
Claim. Encryption 0 ~ 9. Set the password corresponding to 0.1.2.3.4.5.6.7.8.9 to 9.0.8.2.7.4.6.3.1.5. Enter a four-digit number on the keyboard. It is required to output its corresponding password immediately. For example: Input 4925. Output: 7584

chiang999

This has nothing to do with the compilation. It is very simple. It was written in a few minutes without considering the efficiency. The input is four digits (less than four digits.
int main (int argc, char * argv [])
{//0.1.2.3.4.5.6.7.8.9 The corresponding password is 9.0.8.2.7.4.6.3.1.5
    int aa, n [4], num;

    cin >> aa;
    n [0] = aa% 10;
    n [1] = aa / 10% 10;
    n [2] = aa / 100% 10;
    n [3] = aa / 1000;

 for (int i = 0; i <= 3; i ++)
  {
    num = n [i];
    switch (num)
    {
     case 0: n [i] = 9; break;
     case 1: n [i] = 0; break;
     case 2: n [i] = 8; break;
     case 3: n [i] = 2; break;
     case 4: n [i] = 7; break;
     case 5: n [i] = 4; break;
     case 6: n [i] = 6; break;
     case 7: n [i] = 9; break;
     case 8: n [i] = 1; break;
     case 9: n [i] = 5; break;
     default: cout << "error";
    }
  }
  aa = n [0] + 10 * n [1] + 100 * n [2] + 1000 * n [3];
  cout << "Password is:";
  cout << aa;
   return 0;
}

zhanglei88

Requires assembly language. If I use C, I can write.

xsteel

The simple way is to use a mapping table, mapping once.

cancer22

The easiest way:
Write a function that implements the change function, then F5 runs, set a breakpoint at the function entry, and then ALT + 8, copy the assembly generated by the compiler and it is OK

chiang999

According to your requirements, write and pull again. It should be fine.
data segment use16
 buf db 10
         db?
         db 10 dup (?), '$'
         
tab dw t0
        dw t1
dw t2
dw t3
dw t4
dw t5
dw t6
dw t7
dw t8
dw t9
data ends
code segment use16
           assume cs: code, ds: data
beg: mov ax, data
         mov ds, ax
         mov ah, 0Ah
         mov dx, offset buf
         int 21h
        lea bx, buf + 1
mov cx, 4
push bx
loo: pop bx
        inc bx
        sub byte ptr [bx], 30h
         push bx
      mov bl, byte ptr [bx]
        mov bh, 0
       add bx, bx
       mov si, offset tab
     dec cx
     cmp cx, 0
     je looo
       jmp [bx + si]
looo: mov dx, offset buf + 2
           mov ah, 09h
          int 21h

; The password corresponding to 0.1.2.3.4.5.6.7.8.9 is 9.0.8.2.7.4.6.3.1.5
t0: mov byte ptr [bx], 39h
       jmp loo
t1: mov byte ptr [bx], 30h
jmp loo
t2: mov byte ptr [bx], 38h
jmp loo
t3: mov byte ptr [bx], 32h
jmp loo
t4: mov byte ptr [bx], 37h
jmp loo
t5: mov byte ptr [bx], 34h
jmp loo
t6: mov byte ptr [bx], 36h
jmp loo
t7: mov byte ptr [bx], 33h
jmp loo
t8: mov byte ptr [bx], 31h
jmp loo
t9: mov byte ptr [bx], 35h
jmp loo
code ends
            end beg

hzxszmh

C version
int main (int argc, char * argv [])
{
int sz [10] = {9,0,8,2,7,4,6,3,1,5};
char input [5] = {0};
scanf ("% 4s", input);
printf ("% d% d% d% d", sz [input [0]-'0'], sz [input [1]-'0'], sz [input [2]-'0'], sz [input [3]-'0']);
return 0;
}

zhanglei88

Thank you so much