Question

Write a MIPS assembly program that prompts the user first for a string, then for a character. The program should then search the string for the character and print out the number of times the character appears in the string. You can use as many restrictions as you want, just be sure to list them. You must allocate space in the .data segment of your program for the user string.

Answer 1

Answer. Here is MISP program for the gien problem:

.data
msg1: .asciiz "Enter the string "
msg2: .asciiz "Enter the character "
count: .word 10
string: .space 100
character: .space 4
msg3: .asciiz "character  "
msg4: .asciiz "occourred in string "
msg5: .asciiz "times "

.text
.global main
main:
li $t0, 100 # end variable for loop
li $t1, 0 # start variable for loop
li $t2, 0 # to count number of occurrences

la $a0, msg1 # printing the msg1
li $v0, 4
syscall

la $a0, string # taking input string from user
li $a1, 100
  li $v0, 8
syscall

  la $a0, msg2 # printing the msg2
  li $v0, 4
syscall

  la $a0, character # taking input character from user
li $a1, 4
  li $v0, 8
syscall

  la $s0, character
lb $s1, ($s0)
  la $t3, string
lb $a2, ($t3)
syscall

loop:
beq $a2, $zero,end # printing the result, if reached end of the array
beq $a2, $s1, something   
addi $t3, $t3, 1 # incrementing char array
lb $a2, ($t3)
j loop

something:
addi $t2, $t1, 1 # incrementing number of occurences of character

end:
la $a0, msg3
li $v0, 4
syscall

  la $a0, character
li $v0, 11
syscall

  la $a0, msg4
li $v0, 4
syscall

  la $a0, string
li $v0, 4
​​​​​​​ syscall

li $v0, 1
move $a0, $t2
​​​​​​​ syscall

  la $a0, msg5
li $v0, 4
​​​​​​​ syscall