Question

该程序需要输入用户输入并打印出素数的数量，因此如果用户输入“5”则输出“2,3,5,7,11”

我正试图这样做：

    boolean isPrime(int n) {
for(int i=2;i<n;i++) {
    if(n%i==0)
        return false;
}
return true;
}

这是我的汇编代码。现在它似乎永远不会离开test_prime程序。

    .globl main
.text
main:
li $v0, 4               # print welcome message
la $a0, welcome
syscall

la $a0, prompt          # prompt for user input
syscall         

#receive input
li $v0, 5               
syscall
add $s1, $v0, $zero     # $s1 = user input

beq $s1, $zero, quit    # if input == zero, quit

#print 1st prime
li $v0, 1               # print int
addi $a0, $zero, 2      # argument = 2
syscall

li $v0, 4               # print new line
la $a0, line
syscall

addi $s2, $s2, 1        # $s2 = 1 (prime counter)
add $a2, $a0, $zero     # $a2 = $a0

loop:
addi $a2, $a2, 1        # argument++
#beq $s2, $s1, quit     # if prime counter == input, quit
jal test_prime
beq $v1, $zero, loop    # if test_prime returns false, repeat
addi $s2, $s2, 1        # else $s2++
#print next prime
li $v0, 1               # print int
add $a0, $a2, $zero     # argument = $a2
syscall

li $v0, 4               # print new line
la $a0, line
syscall

beq $s2, $s1, quit      # if prime counter == input, quit
j loop

test_prime:
add $t1, $a2, $zero     # $t1 = argument
addi $t2, $zero, 1      # $t2 = 1
loop2:
addi $t2, $t2, 1        # $t2++
beq $t2, $t1, true      # if $t2 == $t1, return
div $t3, $t1, $t2       # $t3 = $t1 / $t2
mfhi $t4                # $t4 = remainder
beq $t4, $zero, false
j loop2
false:
li $v1, 0       # $v1 = false
jr $ra
true:
li $v1, 1       # $v1 = true
jr $ra

quit:
# program exit
li $v0, 10
syscall


.data
welcome:    .asciiz "Prime Numbers\n"   
prompt:     .asciiz "How many primes? "
line:       .asciiz "\n"

Answer 1

这是问题专栏

add $a2, $a0, $zero     # $a2 = $a0

通过将其更改为：

来修复程序

addi $a2, $zero, 2      # $a2 = 2

试图编写一个用MIPS汇编语言打印素数的程序

1 个答案: