c - 在 C 中使用堆栈

Question

我正在尝试实现以下功能它接受一行字符串作为输入，然后将它们标记化并将它们放入堆栈中，然后打印缓冲区反向“欢迎来到书房”谁会出现书房欢迎

到目前为止，我遇到的问题是它停止工作，调试后我意识到在 main 中调用的推送函数中， token 的值没有传递给该函数。

任何人都可以帮我解决为什么它不将 token 字符串传递给推送函数吗？我认为“char* data;”有问题在结构中

#include <stdio.h>
#include <string.h>
#include <stdlib.h> 

// self-referential structure
struct stackNode
{   
   char* data;
   struct stackNode *pNext;
};

typedef struct stackNode StackNode;
typedef StackNode *StackNodePtr;

// function prototypes
void push( StackNodePtr *pTop, char value );
//int pop( StackNodePtr *pTop );
//int isEmpty( StackNodePtr pTop );
void printStack( StackNodePtr pCurrent );


int main( void )
{
    char *pToken = NULL;
    int counter;
    char input[BUFFER_SIZE];
    StackNodePtr pStack = NULL;

    printf("Please enter a line of text here :\n");
    gets(input);

    pToken = strtok(input, " ");

    while(pToken != NULL)
    {
        push(&pStack, pToken);
        printf("%p  '%s'\n", pToken, pToken);
        pToken = strtok(NULL, " ");
    }
    printf("I am out of while loop");
    printStack(pStack); 
    return 0;
}


// Insert a node at the stack top
void push( StackNodePtr *pTop, char* value )
{ 
   StackNodePtr pNew;

   pNew = malloc( sizeof( StackNode ) );

   if ( pNew != NULL )
   {   
      pNew->data = value;
      pNew->pNext = *pTop; // insert at top of stack
      *pTop = pNew;
   }
   else
   {
      printf( "%d not inserted. No memory available.\n", value );
   }
} 

// output stack contents to the console
void printStack( StackNodePtr pCurrent )
{ 
   if ( pCurrent == NULL )
   {
      printf( "The stack is empty.\n\n" );
   }
   else
   { 
      printf( "The stack is:\n" );

      while ( pCurrent != NULL )
      { 

         printf( "%s", pCurrent->data );
         pCurrent = pCurrent->pNext; // move to next element
      }
      printf( "NULL\n\n" );
   } 
}

Answer 1

这有效:

#include <stdio.h>
#include <string.h>
#include <stdlib.h> 
#define BUFFER_SIZE 256

// self-referential structure
struct stackNode
{   
  char* data;
  struct stackNode *pNext;
};

typedef struct stackNode StackNode;
typedef StackNode *StackNodePtr;

// function prototypes
void push(StackNodePtr* pTop, char* value);
//int pop( StackNodePtr *pTop );
//int isEmpty( StackNodePtr pTop );
void printStack( StackNodePtr pCurrent );


int main( void )
{
  char *pToken = NULL;
  int counter;
  char input[BUFFER_SIZE];
  StackNodePtr pStack = NULL;

  printf("Please enter a line of text here :\n");
  gets(input);

  pToken = strtok(input, " ");

  while(pToken != NULL)
  {
    push(&pStack, pToken);
    printf("%p  '%s'\n", pToken, pToken);
    pToken = strtok(NULL, " ");
  }
  printf("I am out of while loop");
  printStack(pStack); 
  return 0;
}


// Insert a node at the stack top
void push( StackNodePtr* pTop, char* value )
{ 
  StackNodePtr pNew;

  pNew = (StackNode*)malloc( sizeof( StackNode ) );

  if ( pNew != NULL )
  {   
    pNew->data = value;
    pNew->pNext = *pTop; // insert at top of stack
    *pTop = pNew;
  }
  else
  {
    printf( "%s not inserted. No memory available.\n", value );
  }
} 

// output stack contents to the console
void printStack( StackNodePtr pCurrent )
{ 
  if ( pCurrent == NULL )
  {
    printf( "The stack is empty.\n\n" );
  }
  else
  { 
    printf( "The stack is:\n" );

    while ( pCurrent != NULL )
    { 

      printf( "%s", pCurrent->data );
      pCurrent = pCurrent->pNext; // move to next element
    }
    printf( "NULL\n\n" );
  } 
}

输入:

welcome to the den

输出:

0x7fff31d13fc0  'welcome'
0x7fff31d13fc8  'to'
0x7fff31d13fcb  'the'
0x7fff31d13fcf  'den'
I am out of while loopThe stack is:
denthetowelcomeNULL

我实际上只是修改了代码以在合理的机器上进行编译。只需确保您没有将字符数组打印为十进制类型即可。我没有修复任何其他问题，所以不能保证，只是这个位可以编译并运行。我假设您稍后会添加它。只需确保您正在跟踪内存分配即可。