sprintf1:
        li      $v0,1   # return:    length of string is 1
        jr      $ra

sprintf:
	move 	$s0, $a0
	move 	$s1, $a1
	move	$s2, $a2
	move 	$s3, $a3
	li   	$s4, 0
	j 	sprintfloop

sprintfloop:
	lb $t0, 0($s1)
	addi $s1, $s1, 1
	beq $t0, '%', checker

	sb $t0, 0($s0)
	addi $s0, $s0, 1
	addi $s4, $s4, 1
	bne $t0, $0, sprintfloop
	jr $ra

checker:
	lb $t0, 0($s1)

	beq $t0, 'd', printd
	beq $t0, 'x', sprintx
	beq $t0, 's', strcpy
	#beq $t0, 'c' sputc
	#beq $t0, '%', sputc
	j	sprintfloop

#######
#       Helper functions

# void printd(int n)
#printd:
#        addi    $sp,$sp,-12    #
 #       sw      $ra,8($sp)     #
#        sw      $s0,4($sp)     # save the old value of $s0
#        sw      $s1,0($sp)     # save the old value of $s1
#
#        li      $s1,10
#        rem     $s0,$a0,$s1    # value % 10
#        addi    $s0,$s0,'0'    # convert that to a digit
#
#        div     $a0,$a0,$s1    # value / 10
#
#        beqz    $a0,onedig     # is it non-zero?
#        jal     printd         # if so, print it


#onedig: move    $a0,$s0        # print the digit we built
#        li      $v0,11  # print_char
#        syscall
#        lw      $s1,0($sp)
#        lw      $s0,4($sp)
#        lw      $ra,8($sp)
#        addi    $sp,$sp,12
#        jr      $ra
# end of printd

printd:
        addi    $sp, $sp, -8    #
        sw      $ra, 0($sp)     #
        sw      $s0, 4($sp)     # save the old value of $s0

	li	$t9, 10		# constant, used for div and rem
        rem     $s0, $s2, $t9   # value % 10
        addi    $s0, $s0, '0'   # convert that to a digit

        div     $a0, $a0, $t9   # value / 10

        beqz    $a0, sonedig     # is it non-zero?
        jal     printd          # if so, print it

sonedig:

	li	$v0, 11		# print_char
	move	$a0, $s0
	syscall

        lw      $s0, 4($sp)
        lw      $ra, 0($sp)
        addi    $sp, $sp, 8
       # move    $s2, $s3
        jr      $ra

strcpy:
	lb $t0, 0($s1)
	addi $s1, $s1, 1
	sb $t0, 0($s0)
	addi $s0, $s0, 1
	bne $t0, $0, strcpy
	jr $ra
# void printx(int value)
#
sprintx:
        addi    $sp, $sp, -8    #
        sw      $ra, 0($sp)     #
        sw      $s0, 4($sp)     # save the old value of $s0

	li	$t9, 16		# constant, used for div and rem
        rem     $s0, $a0, $t9   # value % 16
        addi    $s0, $s0, '0'   # convert that to a digit

        div     $a0, $a0, $t9   # value / 16

        beqz    $a0, xonedig     # is it non-zero?
        jal     sprintx          # if so, print it

xonedig: li	$v0, 11		# print_char
	move	$a0, $s0
	syscall

        lw      $s0, 4($sp)
        lw      $ra, 0($sp)
        addi    $sp, $sp, 8
        jr      $ra
# void bzero(char *buf, int n)
bzero:  beq     $a1,$0,bzexit # while(n>0) {
        sb      $0,0($a0)       # *s = 0
        addi    $a0,$a0,1       # s++
        addi    $a1,$a1,-1      # n--
        j       bzero           # }
bzexit: jr      $ra
# end of bzero