Hello I have a program that will alphabetize a 20 character string the user enters, while also filtering out characters that are not lower case letters. I have the program alphabetizing with a recursive loop, then have a more simple filter set up to weed out the characters that are not lower case letters. I can get the program to correctly alphabetize and filter out the characters, once that happens the program asks if the user wants to try again. This is where I am encountering a problem, when the previous string is longer than the subsequent one there are left over characters printed out.
For example, if the 1st string alphabetizes to abcdefgxyz and the 2nd should only be abcdefg, the output will still show the xyz.
Any help will be greatly appreciated!
Here is my code
.text
main: la $a0, prompt
li $v0, 4
syscall
la $a0, input
li $a1, 21
li $v0, 8
syscall
la $t0, input
la $t7, input
la $t5, final
loop: lb $t1, 0($t0)
lb $t2, 1($t0)
ble $t1, $t2, incr
beqz $t2, filter
jal swap
j loop
incr: addi $t0, $t0, 1
j loop
filter: lb $t3, 0($a0)
blt $t3, 0x61, next
bgt $t3, 0x7a, next
sb $t3, 0($t5)
add $t5, $t5, 1
next: beqz $t3, output
addi $a0, $a0, 1
j filter
output: la $a0, display
li $v0, 4
syscall
la $a0, final
syscall
la $a0, again
syscall
li $v0, 12
syscall
beq $v0, 0x79, clr
j end
clr: li $a0, 0x0a
li $v0, 11
syscall
j main
end: la $a0, termin
li $v0, 4
syscall
li $v0, 10
syscall
swap: sub $sp, $sp, 4
sw $ra, ($sp)
sb $t1, 1($t0)
sb $t2, 0($t0)
beq $t0, $t5, return
sub $t0, $t0, 1
lb $t1, 0($t0)
lb $t2, 1($t0)
ble $t1, $t2, return
jal swap
return: addi $t0, $t0, 1
lw $ra, ($sp)
addi $sp, $sp, 4
jr $ra
.data
prompt: .asciiz "Please enter a string to alphabetize and filter: "
display:.asciiz "\nThe alphabetized and filtered string is: "
again: .asciiz "\nDo you want to try again (y for yes)? "
termin: .asciiz "\nProgram terminated."
input: .space 21
final: .space 21
