CODECARTA

ASSUME DS: DATA, CS: CODE

DATA SEGMENT ; start of data segment

LIST DB 12H,10H,04H,08H ; n (4) number of elements stored in a LIST array

COUNT DB 03H ; n-1 counter value stored in COUNT variable

DATA ENDS ; end of data segment

CODE SEGMENT ; start of code segment

START : MOV AX, DATA ; initializing the data segment

MOV DS, AX

XOR AX, AX ; clear AX register content

MOV CL, COUNT ; store n-1 value (3) in CL register (outer loop count)

BACK2: MOV SI, OFFSET LIST ; set the pointer to the 1^st location of LIST array

MOV BL, CL ; temporally store the n-1 value in BL register (inner loop count)

BACK1: MOV AL, [SI] ; get the 1^st array element, ie. LIST [0] to AL

INC SI ; increment the pointer by 1 to point to the next location

; ie: LIST[SI+1]

CMP AL, [SI] ; compare AL with LIST[SI+1]

JB NEXT ; if 1^st element is less than 2^nd element then go to NEXT to

; decrement the inner loop count value in BL, to indicate one

; comparison is over.

XCHG [SI], AL ; otherwise swap the numbers.

MOV [SI-1], AL

NEXT: DEC BL ; decrement inner loop count value.

JNZ BACK1 ; if inner loop count value is not 0, then go to BACK1 to

; repeat the comparison of remaining elements of LIST array.

LOOP BACK2 ; decrement the outer loop count value in CL register

; (perform n-1 passes)

MOV AH, 4CH ; terminate the program

INT 21H

CODE ENDS ; end of code segment

END START

Output:

D:\MASM> Masm 3a.asm;

D:\MASM> Link 3a.obj;

D:\MASM> TD 3a.exe

Then press F7 to trace the program (line by line execution).

Click on View menu and select Dump to see the output.

CODECARTA | CODE ENCYCLOPEDIA | REFERANCE | WORKSHOP|C/C++