mca_assembly/binary_search.asm at master · avinash-ducs/mca_assembly · GitHub

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DATA SEGMENT

    ARRINP DB "Enter elements of array (in ascending order): $"
    INPUT_ELE DB "Enter number to search: $"
    NOTFOUND_MSG DB "Element not found! $"
    FOUND_MSG DB "Element found! $"
    INPSIZE DB "Enter size of array: $"
    EMPTY DB "Empty array!$"
    ELE DB ?
    ARRAY DB 10 DUP(?)
    SIZE DB ?
    TWO DB 2
    TEN DB 10
    BEG DB ?
    LAST DB ?

DATA ENDS

CODE SEGMENT
    START:
        ASSUME DS:DATA, CS:CODE
        ;LOADING DS AND ES
        MOV AX, DATA
        MOV DS, AX
        MOV ES, AX

        ;USER INPUT SIZE
        MOV AX,0
        LEA DX, INPSIZE
        MOV AH,9
        INT 21H

        CALL NEWLINE

        CALL READ
        CMP BX,0
        JE EMP
        MOV SIZE, BL

        ;INPUT ELEMENTS OF ARRAY

        CALL NEWLINE

        MOV AX,0
        LEA DX, ARRINP
        MOV AH,9
        INT 21H

        CALL NEWLINE

        MOV CX, 0
        MOV CL, SIZE
        MOV DI,0

        ARRAYINPUT:
                MOV BX,0
                CALL READ
                MOV DX, BX
                MOV BX, OFFSET ARRAY
                MOV BX[DI], DX
                INC DI

                CALL NEWLINE

                LOOP ARRAYINPUT

        ;INPUT ELEMENT TO SEARCH

        MOV AX,0
        LEA DX, INPUT_ELE
        MOV AH,9
        INT 21H

        CALL NEWLINE
        MOV BX,0
        CALL READ
        MOV ELE,BL

        ;BINARY SEARCH LOGIC

        MOV BEG, 0
        MOV AL, SIZE
        AND AX, 0FFH
        MOV LAST, AL
        DEC LAST

        SEARCH:
            MOV AL, BEG
            CMP AL, LAST
            JG NOT_FOUND
            ADD AL, LAST
            DIV TWO
            AND AX,0FFH
            MOV SI,AX
            MOV DL,ELE
            CMP DL,BYTE PTR ARRAY[SI]
            JL SMALLER
            JG GREATER
            JE FOUND

        ;ELEMENT TO SEARCH IS SMALLER THAN MIDDLE ELEMENT, UPDATE LAST
        SMALLER:
            MOV LAST,AL
            DEC LAST
            JMP SEARCH

        ;ELEMENT TO SEARCH IS GREATER THAN MIDDLE ELEMENT, UPDATE BEG
        GREATER:
            MOV BEG,AL
            INC BEG
            JMP SEARCH

        ;PRINT ELEMENT FOUND AND DISPLAY ITS INDEX
        FOUND:
            LEA DX,FOUND_MSG
            MOV AH,9H
            INT 21H
            MOV DX,SI
            ADD DL,30H
            MOV AH,2H
            INT 21H
            JMP EXIT

        ;PRINT ELEMENT NOT FOUND
        NOT_FOUND:
            LEA DX,NOTFOUND_MSG
            MOV AH,9H
            INT 21H
            JMP EXIT

        ;PRINT ARRAY EMPTY
        EMP:
            LEA DX,EMPTY
            MOV AH,09H
            INT 21H

     EXIT: HLT

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

     NEWLINE PROC NEAR                  ;PROCEDURE WHICH PRINTS A NEWLINE AND CARRIAGE RETURN ON THE CONSOLE

        MOV AH, 2
        MOV DL, 0DH
        INT 21H
        MOV DL, 0AH
        INT 21H
        RET

     NEWLINE ENDP

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

     READ PROC NEAR                     ;PROCEDURE WHICH READS INPUT FROM USER ONTO THE CONSOLE

        MOV BX,0
        MOV DX,0

        LOOP1:
                MOV AX, 0100H
                INT 21H
                CMP AL,0DH

                JE ENDLOOP
                AND AX,0FH
                XCHG AX,BX
                MUL TEN
                ADD BX,AX
                JMP LOOP1
        ENDLOOP:
                RET

      READ ENDP

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


CODE ENDS
    END START