aeroporto.spim

# 1º Fazer uma array
# 2º Salvar a quantidade de vôos para cada aeroporto.
# 3º Salvar a maior quantidade de vôos em G que um único aeroporto possuí.
# 4º Imprimir todos os aeroportos de {1, ..., A} que possuem G vôos.
.data
	# String que vai ser lida. 4 * 25 chars.
	buffer: .space 12

	# 101 Aeroportos no máximo * 4 bytes.
	aeroportos: .space 404
	#aeroportos: .word 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

.text
	# --------------------------------------------------------------------------------------
	# This procedure reads string from STDIN and parse two integers separated by space {a b}
	# respectively in $v0 and $v1.
	# --------------------------------------------------------------------------------------
	read_integers:
		addi $v0, $zero, 8 # read_string()
		la $a0, buffer
		addi $a1, $zero, 12 # Maximum length of charcters it can read.
		syscall

		# t0 will have the result of the first integer.
		add $t0, $zero, $zero
		# t1 will have the addres of the buffer as it goes forward.
		la $t1, buffer

	parse:
		# Load character into t3
		lb $t3, 0($t1)
		# Go to the next character.
		addi $t1, $t1, 1
		# If character is newline, done with the second integer.
		beq $t3, 10, done_second
		# If character is null, done with the second integer.
		beqz $t3, done_second
		# If character is space, done with the first integer.
		beq $t3, 32, done_first
		# Transform character into number.
		addi $t3, $t3, -48
		# Multiply by 10.
		mul $t0, $t0, 10
		# Add the the new digit.
		add $t0, $t0, $t3
		# Repeat loop.
		j parse

	done_first:
		# Add result of t0 to the apropriate register.
		add $v0, $zero, $t0
		# t0 will have the result of the second integer.
		add $t0, $zero, $zero
		# Parse again.
		j parse

	done_second:
		# Add result of t1 to the apropriate register.
		add $v1, $zero, $t0
		# Return to the procedure caller.
		jr $ra

	# -------------------------------------
	# Zero, as in the verb, all the array.
	# -------------------------------------
	clean_array:
		# Go from the end until the start of the array that we need zeroed.
		add $t0, $zero, $s8

	clean_array_recursive:
		# When t0 is zero, we cleaned it all. Note zero itself does not matter.
		beq $t0, $zero, clean_array_exit
		# Get position of the current index.
		sll $t1, $t0, 2
		# Get address plus position.
		add $t1, $s4, $t1
		# Save byte as zero in memory.
		sw $zero, 0($t1)
		# Go to the previous character.
		addi $t0, $t0, -1
		# Repeat loop.
		j clean_array_recursive

	clean_array_exit:
		# Exit loop.
		jr $ra

	#-----------------------------------------------
	# Main.
	#-----------------------------------------------
	main:
		la $s4, aeroportos    # Endereço de aeroportos.
		addi $s7, $zero, 1    # s7 = s7 + 1 = Testes
		j prepare_main

	#-----------------------------------------------
	# Print procedure.
	#-----------------------------------------------
	print_recursive:
		beq $t0, $t2, print_exit # Base case: when we left.

		sll $t1, $t0, 2   # Get index.
		add $t1, $s4, $t1 # A + i
		lw $t1, 0($t1)    # Get value A[i]

		addi $t0, $t0, 1              # Next position.
		bne $t1, $s5, print_recursive # If t1 is less than the value needed to print, repeat loop

		addi $a0, $t0, -1 # a0 = t1 - 1 = position of item
		#add $a0, $t1, $zero
		addi $v0, $zero, 1  # 1 = print_int()
		syscall

		addi $a0, $zero, 32 # 32 = ' ' in ASCII
		addi $v0, $zero, 11 # 11 = print_char()
		syscall

		j print_recursive

	print_results:
		# Print the words before
		addi $a0, $zero, 84 # 10 = '\n' in ASCII
		addi $v0, $zero, 11 # 11 = print_char()
		syscall
		addi $a0, $zero, 101 # 10 = '\n' in ASCII
		addi $v0, $zero, 11 # 11 = print_char()
		syscall
		addi $a0, $zero, 115 # 10 = '\n' in ASCII
		addi $v0, $zero, 11 # 11 = print_char()
		syscall
		addi $a0, $zero, 116 # 10 = '\n' in ASCII
		addi $v0, $zero, 11 # 11 = print_char()
		syscall
		addi $a0, $zero, 101 # 10 = '\n' in ASCII
		addi $v0, $zero, 11 # 11 = print_char()
		syscall
		addi $a0, $zero, 32 # 10 = '\n' in ASCII
		addi $v0, $zero, 11 # 11 = print_char()
		syscall
		add $a0, $zero, $s7  # a0 = s7
		addi $v0, $zero, 1 # 1 = print_int()
		syscall
		addi $a0, $zero, 10 # 10 = '\n' in ASCII
		addi $v0, $zero, 11 # 11 = print_char()
		syscall

		# Print the numbers.
		add $t2, $zero, $s8 # Max. 100 numbers to read.
		add $t0, $zero, $zero # to = 0
		j print_recursive

	print_exit:
		addi $a0, $zero, 10 # 10 = '\n' in ASCII
		addi $v0, $zero, 11 # 11 = print_char()
		syscall
		syscall

		add $s7, $s7, 1 # More one test.

	#-----------------------------------------------
	# Read test.
	#-----------------------------------------------
	prepare_main:
		jal read_integers

		add $s0, $zero, $v0 # s0 = A
		add $s1, $zero, $v1 # s1 = B
		addi $s8, $s0, 1    # s8 = B + 1

		beq $s0, $zero, exit # Exit quando A ou B for 0.
		beq $s1, $zero, exit # Exit quando A ou B for 0.
		jal clean_array

		add $s5, $zero, $zero # s5 = greatest number of takeoffs of a single airport.

	read_destination:
		beq $s1, $zero, print_results # Volta pro main para ler mais um teste

		jal read_integers
		add $s2, $zero, $v0 # s2 = X
		add $s3, $zero, $v1 # s3 = Y

		sll $s2, $s2, 2 # X *= 4 to get position of X in the array...
		add $s2, $s4, $s2 # X + &A
		lw $s6, 0($s2) # Pegar a pontuação atual desse destino.
		addi $s6, $s6, 1 # ++A[X]
		sw $s6, 0($s2)

		# Greatest number.
		ble $s6, $s5, read_destination_2
		add $s5, $zero, $s6

	read_destination_2:
		sll $s3, $s3, 2 # X *= 4 to get position of X in the array...
		add $s3, $s4, $s3 # X + &A
		lw $s6, 0($s3) # Pegar a pontuação atual desse destino.
		addi $s6, $s6, 1 # ++A[X]
		sw $s6, 0($s3)

		# Greatest number.
		ble $s6, $s5, read_destination_3
		add $s5, $zero, $s6

	read_destination_3:

		addi $s1, $s1, -1 # --B
		j read_destination

	#-----------------------------------------------
	# Exit.
	#-----------------------------------------------
	exit:
		addi $v0, $zero, 10 # 10 = exit()
		syscall