;
; CS1022 Introduction to Computing II 2018/2019
; Lab 2 - Subarray
;

N	EQU	7
M	EQU	3

	AREA	RESET, CODE, READONLY
	ENTRY

	; initialize system stack pointer (SP)
	LDR	SP, =0x40010000
	LDR R1, =LARGE_A
	LDR R2, =SMALL_A
	;
	; Write your program here to determine whether SMALL_A
	;   is a subarray of LARGE_A
	;
	; Store 1 in R0 if SMALL_A is a subarray and zero otherwise
	;

	MOV R0,#0; 	boolean subArray = false
	MOV R3,#0;
forI	     ;
	CMP R3,#N;	for(i = 0; i <array.length;i++)
	BGE endForI;{
	MOV R4,R3;		for(j =0;j <array.length;j++)
forJ	 	 ;		{
	CMP R4,#N
	BGE endForJ

	MOV R7,#N;			r7 = arrayLarge.length
	MUL R7,R3,R7;		r7 = i * arrayLarge.length
	ADD R7,R7,R4;		index = r7 + coloumn[j]
	LDR R7,[R1,R7,LSL#2];r7 = arrayLarge[i][j]

	MOV R8,#0			;r8 = 0
	LDR R8,[R2,R8,LSL#2];r8 = arraySmall[0][0] (We do this as we only have to check if the first element of the small array
						; 						is equal to the element of the large array. This means we only loop when we have an equal element.
	CMP R7,R8			;if(arrayLarge[i][j] == arraySmall[0][0]
	BNE notSubArray		;{
	MOV R0,#1			;	subArray = true;
						;	(We set subArray to true. This stays true unless the next indexs are not equal until we reach the end.)
	MOV R9,R3			;	int x =i
	MOV R5,#0			;
forK					;	for(k = 0; k < arraySmall.length;k++)
	CMP R5,#M			;	{
	BGE endForK			;
	MOV R10,R4			;		int y = j
						;
	MOV R6,#0			;		for(l=0;l<arraySmall.length;l++)
forL					;		{
	CMP R6,#M			;			r6 = arraySmall.length
	BGE endForL			;
	MOV R7,#N			;			r7 = arrayLarge.length
	MUL R7,R9,R7		;			r7 = x * arrayLarge.length(rowsize)
	ADD R7,R7,R10		;			index = x + coloumn(y)
	LDR R7,[R1,R7,LSL#2];			r7 = arrayLarge[x][y]

	MOV R8,#M			;			r8 = arraySmall.length
	MUL R8,R5,R8		;			r8 = k * arrayLarge.length(rowsize)
	ADD R8,R8,R6		;			index = k + coloumn(j)
	LDR R8,[R2,R8,LSL #2];			r8 = arraySmall[k][l]

	CMP	R7,R8			;			if(arrayLarge[x][y] != arraySmall[k][l])
	BEQ isEql			;			{
	MOV R0,#0			;				subArray = false;
isEql					;			}
	ADD R10,R10,#1		;			y++
	ADD R6,R6,#1		;		}
	B	forL			;	}
endForL
	ADD R9,R9,#1		;	x++
	ADD R5,R5,#1		;}
	B	forK			;
endForK
notSubArray
	ADD R4,R4,#1;
	B	forJ	;	}
endForJ
	ADD R3,R3,#1;
	B	forI	;}
endForI
STOP	B	STOP


;
; test data
;

LARGE_A	DCD	 48, 37, 15, 44,  3, 17, 26
		DCD	  2,  9, 12, 18, 14, 33, 16
		DCD	 13, 20,  1, 22,  7, 48, 21
		DCD	 27, 19, 44, 49, 44, 18, 10
		DCD	 29, 17, 22,  4, 46, 43, 41
		DCD	 37, 35, 38, 34, 16, 25,  0
		DCD	 17,  0, 48, 15, 27, 35, 11

SMALL_A	DCD	 49, 44, 18
		DCD	  4, 46, 43
		DCD	 34, 16, 25

	END