Question

int Reverse(int num)
{
    int remainder = 0;
    int rev = 0;
    while ( num != 0)
    {
        remainder = num % 10;
        num = num /10;
        rev = rev * 10 + remainder;
    }
    return rev;
}

void Palindrome()
{
    int num;
        cin >> num;
        Reverse(num);
        cout << num;
        for (int i = 0; i < 10; i++)
        {
            if ( num != Reverse(num))
            {
                num = num + Reverse(num);
                cout << " " << num;
            }
            if ( num == Reverse(num))
            {
                 cout << " ";
            }
        }
 }

我最大的问题是循环。实际的数学并不困难，但我无法弄清楚如何设置循环，尤其是for循环中的if循环。

我把它写成一个整数，然后打印出十次，不同的整数将整数向后添加到自身，反复检查它是否是回文。

主程序已经用MIPS编写，以及rev函数。我只是没有了解我将如何进行Palindrome程序。

任何提示都会非常感激！

我试过这个：

首先我做的循环将继续进行10次。

然后我在回文程序中调用rev函数

jal rev                     # call rev function

la $a0, spaces              # display the number
bne $a0, $v0, then          # if num isnt equal to rev
add $a0, $a0, $t1           # num = num + reverse(num)
la spaces, $a0              # display the added number each time
beq $a0, $v0, then          # if num IS equal to rev

// display spaces instead??

我知道这一定是非常错误但这是我第一次这样做。

Answer 1

我没有更改rev功能，但我不得不更改Palindrome程序以将C编译为MIPS。我无法编译cin或cout（不是那些C ++？）所以cin和cout被注释掉了。

int Reverse(int num)
{
    int remainder = 0;
    int rev = 0;
    while ( num != 0)
    {
        remainder = num % 10;
        num = num /10;
        rev = rev * 10 + remainder;
    }
    return rev;
}

void Palindrome()
{
    int num = 0;
    int i; 
        //cin >> num;
    Reverse(num);
        //cout << num;

    for (i = 0; i < 10; i++)
        {
            if ( num != Reverse(num))
            {
                num = num + Reverse(num);
                //cout << " " << num;
            }
            if ( num == Reverse(num))
            {
                 //cout << " ";
            }
        }
 }

int main ( int argc , char * argv [] )
{
   return 0;
}




 # -G value = 8, Cpu = 3000, ISA = 1
 # GNU C version cygnus-2.7.2-970404 (mips-mips-ecoff) compiled by GNU C version cygnus-2.7.2-970404.
 # options passed:  -msoft-float
 # options enabled:  -fpeephole -ffunction-cse -fkeep-static-consts
 # -fpcc-struct-return -fcommon -fverbose-asm -fgnu-linker -msoft-float
 # -meb -mcpu=3000

gcc2_compiled.:
__gnu_compiled_c:
    .text
    .align  2
    .globl  Reverse
    .ent    Reverse
Reverse:
    .frame  $fp,16,$31      # vars= 8, regs= 1/0, args= 0, extra= 0
    .mask   0x40000000,-8
    .fmask  0x00000000,0
    subu    $sp,$sp,16
    sw  $fp,8($sp)
    move    $fp,$sp
    sw  $4,16($fp)
    sw  $0,0($fp)
    sw  $0,4($fp)
$L2:
    lw  $2,16($fp)
    bne $2,$0,$L4
    j   $L3
$L4:
    lw  $2,16($fp)
    li  $3,1717960704           # 0x66660000
    ori $3,$3,0x6667
    mult    $2,$3
    mfhi    $6
    sra $3,$6,2
    sra $4,$2,31
    subu    $3,$3,$4
    move    $5,$3
    sll $4,$5,2
    addu    $4,$4,$3
    sll $3,$4,1
    subu    $2,$2,$3
    sw  $2,0($fp)
    lw  $2,16($fp)
    li  $3,1717960704           # 0x66660000
    ori $3,$3,0x6667
    mult    $2,$3
    mfhi    $6
    sra $3,$6,2
    sra $4,$2,31
    subu    $2,$3,$4
    sw  $2,16($fp)
    lw  $2,4($fp)
    move    $4,$2
    sll $3,$4,2
    addu    $3,$3,$2
    sll $2,$3,1
    lw  $3,0($fp)
    addu    $2,$2,$3
    sw  $2,4($fp)
    j   $L2
$L3:
    lw  $3,4($fp)
    move    $2,$3
    j   $L1
$L1:
    move    $sp,$fp         # sp not trusted here
    lw  $fp,8($sp)
    addu    $sp,$sp,16
    j   $31
    .end    Reverse
    .align  2
    .globl  Palindrome
    .ent    Palindrome
Palindrome:
    .frame  $fp,32,$31      # vars= 8, regs= 2/0, args= 16, extra= 0
    .mask   0xc0000000,-4
    .fmask  0x00000000,0
    subu    $sp,$sp,32
    sw  $31,28($sp)
    sw  $fp,24($sp)
    move    $fp,$sp
    sw  $0,16($fp)
    lw  $4,16($fp)
    jal Reverse
    sw  $0,20($fp)
$L6:
    lw  $2,20($fp)
    slt $3,$2,10
    bne $3,$0,$L9
    j   $L7
$L9:
    lw  $4,16($fp)
    jal Reverse
    lw  $3,16($fp)
    beq $3,$2,$L10
    lw  $4,16($fp)
    jal Reverse
    lw  $3,16($fp)
    addu    $2,$3,$2
    sw  $2,16($fp)
$L10:
    lw  $4,16($fp)
    jal Reverse
    lw  $3,16($fp)
    bne $3,$2,$L8
$L11:
$L8:
    lw  $2,20($fp)
    addu    $3,$2,1
    sw  $3,20($fp)
    j   $L6
$L7:
$L5:
    move    $sp,$fp         # sp not trusted here
    lw  $31,28($sp)
    lw  $fp,24($sp)
    addu    $sp,$sp,32
    j   $31
    .end    Palindrome
    .align  2
    .globl  main
    .ent    main
main:
    .frame  $fp,24,$31      # vars= 0, regs= 2/0, args= 16, extra= 0
    .mask   0xc0000000,-4
    .fmask  0x00000000,0
    subu    $sp,$sp,24
    sw  $31,20($sp)
    sw  $fp,16($sp)
    move    $fp,$sp
    sw  $4,24($fp)
    sw  $5,28($fp)
    jal __main
    move    $2,$0
    j   $L12
$L12:
    move    $sp,$fp         # sp not trusted here
    lw  $31,20($sp)
    lw  $fp,16($sp)
    addu    $sp,$sp,24
    j   $31
    .end    main

如何将此C转换为MIPS？

1 个答案: