lab5.asm

assume cs: code, ds: data

data segment
    dummy db 0Ah, '$'
    aLen db ?
    bLen db ?
    cLen db ?
    msg1Num db 'Enter first number line:', 10, 13, '$'
    msg2Num db 'Enter second number line:', 10, 13, '$'
    msgRes  db 'Result:', 10, 13, '$'
    tab  db 10, 13, '$'
    a db 40, 40 dup(0)
    b db 40, 40 dup(0)
    c db 40, 40 dup(0)
data ends

code segment

read proc
    push  bp
    mov   bp, sp

    mov   ah,0ah
    mov   dx, [bp+4]
    int   21h
    pop   bp
    ret   2
read endp

print proc
    push  bp
    mov   bp, sp

    mov   ah,09h
    mov   dx, [bp+4]
    int   21h
    pop   bp
    ret   2
print endp

addInt proc
    push    bp
    mov bp, sp

    mov bx, [bp+4]
    mov cl, byte ptr [bx+1] ; len(b)
    mov bLen, cl

    xor ax, ax
    mov dx, [bp+6]
    mov si, [bp+6]
    mov al, byte ptr [si+1] ; len(a)
    mov aLen, al

    cmp al, cl ; bx = b ; dx = a = si
    jle a1

    mov dx, bx
    mov bx, si

a1:
    mov cl, bLen
    inc cl
    mov cLen, cl
    mov di, [bp+8]
    mov byte ptr [di+1], cl ; cLen
    mov byte ptr [di+2], '0' ; cLen
    mov cl, bLen
    mov si, bx
    mov cl, byte ptr [si+1]
    add si, 2
    add di, 3
    rep movsb
    mov byte ptr [di], '$'

    dec di ; last digit 'c'
    mov si, dx ; a
    mov cl, aLen
    inc cl
    add si, cx
    dec cl
    mov ch, cLen

    xor dx, dx
    std
    sum:
        mov bl, byte ptr [di]
        sub bl, 30h ;
        add bl, byte ptr [si]
    cycle:sub bl, 30h ; temp sum
        cmp dl, 1
        je one
        ret1: cmp bl, 9h
        jg rem

        ret2: add bl, 30h
        mov byte ptr [di], bl
        dec si
        dec di
        dec cl
        dec ch
        cmp cl, 0
        jg sum
        cmp ch, 0
        jg more

    cmp dl, 1
    je last

    ret3: jmp endd

    more:
    mov bl, byte ptr [di]
    jmp cycle

    last: mov dl, 0
        add byte ptr [di], 1h
    jmp ret3

    rem: mov dl, 1
        sub bl, 0ah
    jmp ret2

    one: inc bl
        mov dl, 0
    jmp ret1

    endd:
    pop bp
    pop bx

    push ax
    push offset c ;;;;;;;;; return
    push bx
    ret
addInt endp

start:  mov ax, data
        mov ds, ax
        mov es, ax

        push offset msg1Num
        call print

        push offset a
        call read

        push offset tab
        call print

        push offset msg2Num
        call print

        push offset b
        call read

        push offset tab
        call print

        push offset msgRes
        call print

        push offset c ; +8
        push offset a ; +6
        push offset b ; +4

        call addInt
        pop dx
        add dx, 2
        push dx
        call print

        mov ah, 4ch
        int 21h
        code ends
end start