Irvine Assembly: merging two different sized arrays

Question

Im trying to merge these two sorted arrays together. I know the problem is when the program is trying to compare the first array after reaching its size limit, but I'm at a loss at figuring out how to get past this. Any help would be really appreciated.

include irvine32.inc
Title ArrayMerge

.data
a1  dw 1,3,4,7,9,15,17
a2  dw 2,6,8,10,11,14,18,19
a3  dw 15 dup(0)

.code
main proc
    sub     EAX,EAX
    mov     ESI,OFFSET a1
    mov     EDI,OFFSET a2
    mov     EDX,OFFSET a3

    call    Merge
    call    Display
    exit
main endp

;=====================================================================
Merge proc
    mov     ECX,lengthof a3 ;Set loop times
TheLoop:
TheJump:
    mov     ax,[ESI]
    cmp     ax,[EDI]
    jl      AddA1  ;Jump if less
    jg      AddA2  ;Jump if greater
    Loop    TheLoop
    jmp     EndJump
AddA1:
    mov     ax,[ESI]
    mov     [EDX],ax
    add     ESI,2
    add     EDX,2
    jmp     TheJump

AddA2:
    mov     ax,[EDI]
    mov     [EDX],ax
    add     EDI,2
    add     EDX,2
    jmp     TheJump

EndJump:
    ret
Merge endp
;==================================================================
Display proc
    mov     ECX,lengthof a3 ;Set loop times
    mov     EDX,offset a3

DisplayLoop:
    mov     ax,[EDX]
    add     EDX,2
    call    writedec
    call    crlf
    loop    DisplayLoop
    ret
Display endp
;===================================================================
end main

Answer 1

You should maintain separate counters for how many elements you have processed from each array. Once you reach the end of either of them, just copy the remaining elements from the other. Also note if elements are equal you don't copy but you should.

i = j = k = 0;
while(i < length1 && j < length2)
{
    switch(compare(src1[i], src2[j]))
    {
        case -1: // src1 is less, copy it
            dst[k++] = src1[i++];
            break;
        case 0:  // equal, copy src2 but also increment i
            i++;
            // fall-through
        case 1:  // src2 is less, copy it
            dst[k++] = src2[j++];
    }
}
// at this point we have reached the end of one of the arrays
// just copy remaining elements
// note only one of these loops will do anything
while(i < length1)
{
    dst[k++] = src1[i++];
}
while(j < length2)
{
    dst[k++] = src2[j++];
}