GCD

%OUT-------------------------------------------------------------------------

%OUT- Computes GCD of a given set of Integers          

%OUT- output: GCD of the set of numbers   

%out – author: Ayon and Ariyam                                            

%OUT-------------------------------------------------------------------------

if1

include macrolib.lby         ;contains common macros

endif

.model small

.stack

.data

array db 10 dup(?)                                                ;the array to store values

count dw 1 dup(?)                                                ;array length

i_msg db "How many elements? ","$"

str_msg db "Input 6 two-digit nos. ","$"

msg db " Enter No. ","$"

out_msg db " GCD of the Nos. is ","$"

.code

;---------------------------------------------------

; Computes the gcd of two numbers

; input: nos. are in BL & BH

; ouput: gcd will be in BL

; regs. affected: BX & AX

;---------------------------------------------------

gcd proc                  ;supply the two nos. in BL & BH

            pushf

            mov ax,0000h

            cmp bl,bh

            jb ok               ;(BL)<(BH), no xchg needed

            xchg bl,bh    ;else exchange

ok:       mov al,bh

lp:        div bl

            cmp ah,00h ;check if remainder zero

            je done

;remainder not zero

            mov al,bl

            mov bl,ah     ;final result will be in BL

            mov ah,00h

            jmp lp

done:

            popf

            ret

gcd endp    

           

main proc

            mov ax,@data

            mov ds,ax

;accept data

            showmsg i_msg

            input                                      ;call input macro to take no. of values

            lea bx,count

            mov [bx],al                          ;store the count value

            input_array array,count,msg

            mov si,00h

            mov cx,count

            dec cx

            mov bl,array[si]

lp1:

            inc si

            mov bh,array[si]

            call gcd

            loop lp1

            mov bh,bl

            showmsg out_msg

            output

            exit

main endp

end main