Lab 6
Lab 6 : Programming based on Sorting of An Array of Numbers
OBJECTIVE
To learn to sort the given data in to ascending & descending order.
PRELAB
Read instructions related to Branch and Subroutine Call.
INSTRUCTIONS
Instructions | Operands | Description |
CALL | procedure name
label | Transfers control to procedure, return address is (IP) pushed to stack. |
RET
| No operands
Or even immediate date | Return from near procedure.
Algorithm:
• Pop from stack:
◦ IP
if immediate operand is present: SP = SP + operand |
EXERCISE
1) Write an ALP to find the largest number from an array.
; ALP to find the largest number from an array
.MODEL SMALL
.STACK 100H
.DATA
ARRAY DB 5, 12, 3, 8, 15, 1, 9 ; Example array
LEN EQU $-ARRAY ; Length of array
LARGEST DB ? ; Variable to store largest number
.CODE
MAIN PROC
MOV AX, @DATA
MOV DS, AX
MOV CX, LEN ; Set counter to array length
MOV SI, 0 ; Initialize index
MOV AL, ARRAY[SI] ; Assume first element is largest
MOV LARGEST, AL ; Store in LARGEST
LOOP_START:
CMP ARRAY[SI], AL ; Compare current element with AL
JLE NEXT_ITER ; If less or equal, move to next iteration
MOV AL, ARRAY[SI] ; If greater, update AL
MOV LARGEST, AL ; Update LARGEST
NEXT_ITER:
INC SI ; Move to next element
LOOP LOOP_START ; Decrement CX and continue if not zero
; At this point, LARGEST contains the largest number
MOV AH, 4CH ; DOS function to exit program
INT 21H
MAIN ENDP
END MAIN2) Write an ALP to find the smallest number from an array.
; ALP to find the smallest number from an array
.MODEL SMALL
.STACK 100H
.DATA
ARRAY DB 5, 12, 3, 8, 15, 1, 9 ; Example array
LEN EQU $-ARRAY ; Length of array
SMALLEST DB ? ; Variable to store smallest number
.CODE
MAIN PROC
MOV AX, @DATA
MOV DS, AX
MOV CX, LEN ; Set counter to array length
MOV SI, 0 ; Initialize index
MOV AL, ARRAY[SI] ; Assume first element is smallest
MOV SMALLEST, AL ; Store in SMALLEST
LOOP_START:
CMP ARRAY[SI], AL ; Compare current element with AL
JGE NEXT_ITER ; If greater or equal, move to next iteration
MOV AL, ARRAY[SI] ; If smaller, update AL
MOV SMALLEST, AL ; Update SMALLEST
NEXT_ITER:
INC SI ; Move to next element
LOOP LOOP_START ; Decrement CX and continue if not zero
; At this point, SMALLEST contains the smallest number
MOV AH, 4CH ; DOS function to exit program
INT 21H
MAIN ENDP
END MAIN3) Write an ALP to sort the given array of numbers in ascending order.
; ALP to sort the given array of numbers in ascending order
.MODEL SMALL
.STACK 100H
.DATA
ARRAY DB 5, 12, 3, 8, 15, 1, 9 ; Example array
LEN EQU $-ARRAY ; Length of array
.CODE
MAIN PROC
MOV AX, @DATA
MOV DS, AX
MOV CX, LEN ; Set outer loop counter
DEC CX ; Decrement by 1 for N-1 passes
OUTER_LOOP:
MOV BX, CX ; Set inner loop counter
MOV SI, 0 ; Reset array index
INNER_LOOP:
MOV AL, ARRAY[SI] ; Load current element
CMP AL, ARRAY[SI+1]; Compare with next element
JLE NEXT_ITER ; If in order, move to next iteration
; Swap elements if out of order
XCHG AL, ARRAY[SI+1]
MOV ARRAY[SI], AL
NEXT_ITER:
INC SI ; Move to next element
DEC BX ; Decrement inner loop counter
JNZ INNER_LOOP ; Continue inner loop if not zero
LOOP OUTER_LOOP ; Continue outer loop
; At this point, the array is sorted in ascending order
MOV AH, 4CH ; DOS function to exit program
INT 21H
MAIN ENDP
END MAIN4) Write an ALP to sort the given array of numbers in descending order.
; ALP to sort the given array of numbers in descending order
.MODEL SMALL
.STACK 100H
.DATA
ARRAY DB 5, 12, 3, 8, 15, 1, 9 ; Example array
LEN EQU $-ARRAY ; Length of array
.CODE
MAIN PROC
MOV AX, @DATA
MOV DS, AX
MOV CX, LEN ; Set outer loop counter
DEC CX ; Decrement by 1 for N-1 passes
OUTER_LOOP:
MOV BX, CX ; Set inner loop counter
MOV SI, 0 ; Reset array index
INNER_LOOP:
MOV AL, ARRAY[SI] ; Load current element
CMP AL, ARRAY[SI+1]; Compare with next element
JGE NEXT_ITER ; If in order (descending), move to next iteration
; Swap elements if out of order
XCHG AL, ARRAY[SI+1]
MOV ARRAY[SI], AL
NEXT_ITER:
INC SI ; Move to next element
DEC BX ; Decrement inner loop counter
JNZ INNER_LOOP ; Continue inner loop if not zero
LOOP OUTER_LOOP ; Continue outer loop
; At this point, the array is sorted in descending order
MOV AH, 4CH ; DOS function to exit program
INT 21H
MAIN ENDP
END MAIN