#Application 14
.text 0x00400000		#Code section

					#Display the message "String:"
	li $v0,4			#Load the function number
	la $a0,read_string	#Load the message starting address
	syscall			#Function call

					#Read string (keyboard)
	li $v0,8			#Load the function number
	la $a0,string		#Load the starting address 
					#for storing the string

	
	li $a1,8			#Set string length
	syscall			#Function call

	li $t1,0			#Counter for reading 
					#the string from memory
again:

	lb $t2,string($t1)	#Load symbol (byte) 
					#from address string+$t1
	sub $t2,$t2,97		#Convert ASCII to deviation
	lb $t3,stats($t2)	#Load current occurrence
					#frequency counter
	add $t3,$t3,1		#Update counter
	sb $t3,stats($t2)	#Store counter in the same address	add $t1,$t1,1		#Update loop counter
	ble $t1,7,again	#While the whole string has not been 
					#read, go to again

					#Display statistics (histogram)						#New line
	li $v0,4			#Load the function number
	la $a0,line		#Load the message starting address
	syscall			#function call

	li $t1,0			#Counter for occurrence 
					#frequency array 
again2:
	lb $t2,stats($t1)	#Load counter in stats+$t1
	beqz $t2,stats0	#If the counter is zero, go to
					#stats0 (display “-“)
	again3:
					#Display asterisks if the 
					#counter is not zero 
		li $v0,4		#Load the function number 
		la $a0,star	#Load the message starting address
		syscall		#Function call
		add $t2,$t2,-1	#Update asterisks counter 
	bgtz $t2,again3	#While the counter in not zero, 
					#go to again3
syn:
					#New line
	li $v0,4			#Load the function number
	la $a0,line		#Load the message starting address
	syscall			#Function call

add $t1,$t1,1			#Update counter
ble $t1,7,again2		#While the array end is not reached

					#Program termination
	li $v0,10			#Load the function number
	syscall			#Function call

					#Display “-“ for a non-existing 
					#symbol in the string 
stats0:
	li $v0,4			#Load the function number
	la $a0,tip		#Load the message starting address
	syscall			#Function call
	j syn			#Return to main loop

.data				#Data section

read_string: 	.asciiz "String:"
star:		.asciiz "*"
string:		.space 8	#Reserve string area 
stats:		.space 8	#Occurrence frequency array
line: 		.asciiz "\n"
msg: 		.asciiz "\nstats="
tip: 		.asciiz "\n-"