Unix 中的 C 解析错误

Question

对于我的一生，我无法弄清楚我的程序正在解析而不是编译。我所有的括号似乎都是正确的。谢谢!

我手头的任务是:

You are required to write a C program that accepts two decimal integers, say d and r. You may assume that the rst decimal integer d is nonnegative and that the second decimal integer r which represents the radix, will be one of 2, 3, 4, : : :, 15, 16. The program should convert the rst decimal integer d into its representation in radix r and print the result. Examples: (i) Suppose the rst decimal integer is 138 and the second decimal integer is 16. In this case, the output produced by your program should be 8A, which is the hexadecimal (radix 16) representation of the decimal integer 138. (ii) Suppose the rst decimal integer is 284 and the second decimal integer is 13. In this case, the output produced by your program should be 18B, which is the radix 13 representation of the decimal integer 284. (In base 13, the digits used are 0, 1, 2, : : :, 9, A, B and C, where A, B and C represent 10, 11 and 12 respectively.) Your program should be written so that it handles just one pair of integers. Thus, the outline for your program is as follows. (Note that no error checks are needed.) 1. Prompt the user to type two decimal integers. 2. Read the two integers. 13. Convert the rst integer into its representation in the radix specied by the second integer. 4. Print the representation and stop. Your program must read the two integers from stdin and write the answer to stdout. You may assume that when prompted, the user will type two integers separated by one or more spaces. Note: Recall that for any radix r 2, the digits to be used are 0, 1, : : :, r 1. Use the letters A, B, C, D, E and F to represent 10, 11, 12, 13, 14 and 15 respectively, as done in the hexadecimal system. Thus, representations in radix 11 can use the digits 0, 1, : : :, 9, A; representations in radix 12 can use 0, 1, : : :, 9, A, B, and so on.� Blockquote

到目前为止我的代码是:

#include <stdio.h>
#include <stdlib.h>
#define OFFA 55
#define OFF0 48

struct charNode{
  char digit;


struct charNode *next;}; struct charNode *head;
int NextParse(int *, int);
char charint( int ); char pop();
void push( char );



struct charNode *newCharNode( );
int main(void)

{int decimal,radix;

  printf( "Two num required:\n" );
  scanf( "%d%d", &decimal, &radix );
  do{push( charint( NextParse( &decimal, radix )));}



  while( decimal >0 );
  while( head != NULL )

  {printf( "%c", pop( ) );}
  printf( "\n" ); return 0;}



int NextParse( int *decimal,int radix )
{ int digit=*decimal%radix; *decimal = *decimal/radix;

  return digit;

char (int x) {
  if ( x > 35 )
  {
    printf("This radix is too large, try again"); exit(1);
  }
  else if (x > = 10) return (char) (x + OFFA);
  else return (char) (x + OFF0);
  }

void push(char digit) {
  struct charNode *temp; 
  if (head == NULL) {
    head = newCharNode(); head -> digit = digit; head -> next = NULL;}
  else {temp= newCharNode( ); temp -> digit=digit; temp -> next=head;head=temp;}
}
char pop(void) {
  char digit; struct charNode *temp;
  if (head == NULL) {
    printf("Cannot complete this task. Empty s tack");
    exit(2);}
  else {
    temp = head; digit = head -> digit;
    head = head -> next; free(temp); return digit;}}

struct charNode *newCharNode(void) {
 struct charNode *memory = (struct charNode *) malloc(sizeof(struct charNode)); //memory adress for new node
 if (memory == NULL) {
   printf("Could not allocate memory"); exit(3);
 }
 else return memory;
}

感谢您的帮助。

Answer 1

假设上面发布的代码是正确的，这里是代码的更好格式版本。我绝对不保证它能达到您想要的效果，除了编译器在编译它时不会立即崩溃这一事实之外。

/*
 * As suggested by pbond, pick a coding style and stick with it.  The
 * original code rather looked like you were using some IDE that was
 * deliberately hiding the formatting issues from you.  Here's the
 * code (sort of) corrected to one of many standards.
 */
#include <stdio.h>
#include <stdlib.h>
#define OFFA 55
#define OFF0 48

struct charNode {
  char digit;
  struct charNode *next;
};

struct charNode *head;

int NextParse(int *, int);
char charint( int );
char pop();
void push( char );
struct charNode *newCharNode( );

int main(void)
{
  int decimal,radix;

  printf( "Two num required:\n" );
  scanf( "%d%d", &decimal, &radix );
  do {
    push( charint( NextParse( &decimal, radix )));
  } while( decimal >0 );

  while( head != NULL ) {
    printf( "%c", pop( ) );
  }

  printf( "\n" );
  return 0;
}



int NextParse( int *decimal,int radix )
{
  int digit= *decimal % radix;
  *decimal = *decimal / radix;

  return digit;
}

/*
 * Here's where one of the errors was.  'NextParse' had not been terminated.  I've
 * added the closing bracket.
 */

/*
 * This is the other error.  It looked like it was supposed to be
 * the 'charint' function declared earlier.  However, the original
 * "char (int x)" wouldn't have passed the compiler.  That combined
 * with the failure to terminate 'NextParse' above, and a possibly
 * less than helpful compiler, lead to confusing syntax error messages.
 * The 'gcc' compiler correctly spotted the "char (int" error, and visual
 * examination after straightening out the style showed the 'NextParse'
 * error above.
 */
char charint (int x)
{
  if ( x > 35 )
    {
      printf("This radix is too large, try again"); exit(1);
    }
  else if (x >= 10)
    return (char) (x + OFFA);
  else
    return (char) (x + OFF0);
}

void push(char digit)
{
  struct charNode *temp; 
  if (head == NULL)
    {
      /*
       * Concatenating lines may look 'neat', but it makes maintenance a lot harder.
       */
      head = newCharNode();
      head -> digit = digit;
      head -> next = NULL;
    }
  else {
    temp= newCharNode( );
    temp -> digit=digit;
    temp -> next=head;
    head=temp;
  }
}

char pop(void) {
  char digit;
  struct charNode *temp;
  if (head == NULL)
    {
      printf("Cannot complete this task. Empty s tack");
      exit(2);
    }
  else
    {
      temp = head;
      digit = head -> digit;
      head = head -> next;
      free(temp);
      return digit;
    }
}

struct charNode *newCharNode(void) {
  struct charNode *memory
    = (struct charNode *) malloc(sizeof(struct charNode)); //memory adress for new node
  if (memory == NULL)
    {
      printf("Could not allocate memory");
      exit(3);
    }
  else
    return memory;
}

如果您使用 IDE，我建议您选择以下两种方法之一:

1) 了解如何调整 IDE，以便将您的代码置于标准样式。

2) 选择一个不同的 IDE，这个 IDE 隐藏得太多，并且您报告的错误消息信息不是很丰富。

如果您没有使用 IDE，我建议您使用一个 IDE 并使用上面的建议 (1)。

您选择哪种 IDE 取决于您的环境以及您的个人喜好/风格。 IDE 争论本质上几乎是宗教性的，因此我无意就使用哪种 IDE 提出任何建议；只是您学会了如何正确使用它。

调整不当的 IDE 会给您带来比其他任何事情都更痛苦的痛苦。