#NB queste soluzioni sono prese
# da AdE_assembly_220903.s

        .text
        .globl main

main:
        subu $sp,$sp,8
        sw $ra,4($sp)
        li $v0,4
        la $a0,prompt1
        syscall
        jal replaceTest
        li $v0,4
        la $a0,prompt2
        syscall
        jal wordsTest

        li $v0,4
        la $a0,prompt7
        syscall
        jal orderedPrefixTest
        li $v0,4
        la $a0,prompt8
        syscall
        jal isOrderedTest
        lw $ra,4($sp)
        addu $sp,$sp,8
        jr $ra

        .data
prompt1:.asciiz "\nreplaceTest: "
prompt2:.asciiz "\nwordsTest: "
prompt7:.asciiz "\norderedPrefixTest: "
prompt8:.asciiz "\nisOrderedTest: "


        .text

# esercizio 1
#       $a0 puntatore ad una stringa
#       $a1 carattere 1
#       $a2 carattere 2

rep:    sb $a2,($a0)
norep:  addu $a0,$a0,1
replace:lbu $t0,($a0)
        beq $t0,$a1,rep
        bnez $t0,norep
        jr $ra


# esercizio 2

replaceTest:
        subu $sp,$sp,8
        sw $ra,4($sp)
        la $a0,replaceStr
        lbu $a1,replaceChar
        lbu $a2,replaceChar+1
        jal replace
        la $a0,replaceStr
        li $v0,4
        syscall
        lw $ra,4($sp)
        addu $sp,$sp,8
        jr $ra

        .data
replaceStr: .asciiz "stringa da modificare"
replaceChar: .byte ' ','_'

        .text

# esercizio 3
#       $a0 puntatore ad una stringa

words:  subu $sp,$sp,8
        sw $ra,4($sp)
        sw $a0,0($sp)
        li $a1,' '
        li $a2,0
        jal replace
        lw $v0,0($sp)
        lw $ra,4($sp)
        addu $sp,$sp,8
        jr $ra


# esercizio 4

wordsTest:
        subu $sp,$sp,8
        sw $ra,4($sp)
        la $a0,wordsString
        jal words
        move $a0,$v0
        li $v0,4
        syscall
        lw $ra,4($sp)
        addu $sp,$sp,8
        jr $ra

        .data
wordsString: .asciiz "uno due tre"



        .text

# esercizio 1
#       $a0 puntatore array di interi a 32 bit senza segno

orderedPrefix:
        li $v0,0
        lw $t1,($a0)
        beqz $t1,end4
loop4:  addu $v0,$v0,1
        addu $a0,$a0,4
        move $t0,$t1
        lw $t1,($a0)
        blt $t0,$t1,loop4
end4:   jr $ra


# esercizio 2

orderedPrefixTest:
        subu $sp,$sp,8
        sw $ra,4($sp)
        la $a0,orderedArray
        jal orderedPrefix
        move $a0,$v0
        li $v0,1
        syscall
        lw $ra,4($sp)
        addu $sp,$sp,8
        jr $ra

        .data
orderedArray: .word 2,5,7,7,6,25,0


        .text

# esercizio 3
#       $a0 puntatore array di interi a 32 bit senza segno

isOrdered:
        subu $sp,$sp,8
        sw $ra,4($sp)
        sw $a0,0($sp)
        jal orderedPrefix
        lw $a0,0($sp)
        sll, $v0,$v0,2
        addu $a0,$a0,$v0
        lw $t0,($a0)
        li $v0,1
        beqz $t0,end5
        li $v0,0
end5:   lw $ra,4($sp)
        addu $sp,$sp,8
        jr $ra


# esercizio 4

isOrderedTest:
        subu $sp,$sp,8
        sw $ra,4($sp)
        la $a0,isOrderedArray
        jal isOrdered
        move $a0,$v0
        li $v0,1
        syscall
        lw $ra,4($sp)
        addu $sp,$sp,8
        jr $ra

        .data
isOrderedArray: .word 2,5,15,25,30,0