為什么我的鏈表在被遍歷時會跳過第一個節點？

我正在學習 C，目前正在學習動態記憶體分配和鏈表，但遇到了問題。我找到了這篇文章并遵循了答案。但是，我的程式在列印出來時仍然跳過了我的第一個節點。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct record
{
  int id;
  char name[257];
  float age;
  struct record *next;
};

int main(void)
{

  int i = 1;
  struct record *firstrecord = (struct record *)malloc(sizeof(struct record));
  firstrecord->id = 1000;
  char firstname[] = "John Doe";
  memcpy(firstrecord->name, firstname,strlen(firstname)   1);
  firstrecord->age = 24.5;
  firstrecord->next = NULL;

  struct record *mostrecentlycreated = firstrecord;

  int iyes = 1;
  char cyes;
  int yes = 1;
  while (yes == iyes)
  {
    
      // build next node
      mostrecentlycreated->next = (struct record *)malloc(sizeof(struct record));
      // change data in new record
      int newid;
      char newname[257];
      char temp;
      float newage;
      char cnewage[257];
    
      printf("Enter the name: ");
      fgets(newname,257,stdin);
    
      newid = 1000   i;

      printf("Enter the person's age: ");
      fgets(cnewage,257,stdin);
      newage = atof(cnewage);
    
      mostrecentlycreated->id = newid;
      memcpy(mostrecentlycreated->name,newname,strlen(newname)   1);
      mostrecentlycreated->age = newage;
      mostrecentlycreated = mostrecentlycreated->next;
      mostrecentlycreated->next = NULL;


      i  ;
      // decide whether or not to keep going
      printf("Do you wish to continue? 1\\0 ");
      
      fgets(&cyes,1,stdin);
      iyes = atoi(&cyes);
    
    
      scanf("%c",&temp);
    
  }
  struct record *traverse = firstrecord;
  while (traverse != NULL)
  {
    printf("Employee id is %i; Employee Name is %s; Employee Age is %f\n",traverse->id,traverse->name,traverse->age);
    traverse = traverse->next;
  }

  free(firstrecord);
  free(mostrecentlycreated);
  return 0;
}

這是我的輸出：

Enter the name: john doe
Enter the person's age: 23
Do you wish to continue? 1\0 0
Employee id is 1001; Employee Name is john doe
; Employee Age is 23.000000
Employee id is 0; Employee Name is ; Employee Age is 0.000000

為什么不列印第一人稱？

uj5u.com熱心網友回復：

創建第一個節點后，您的回圈會在每次迭代中創建一個新節點，但它將用戶的輸入分配給串列中的前一個節點，而不是添加到串列中的當前節點。因此，在第一次迭代中，您將覆寫第一個節點的資料，然后附加第二個空節點。然后在第二次迭代中，您將覆寫第二個節點的資料，并附加一個空白的第三個節點。等等。

試試這個：

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

struct record
{
  int id;
  char name[257];
  float age;
  struct record *next;
};

int main(void)
{
  int i = 1;

  struct record *firstrecord = (struct record *)malloc(sizeof(struct record));
  firstrecord->id = 1000;
  strncpy(firstrecord->name, "John Doe", 257);
  firstrecord->age = 24.5;
  firstrecord->next = NULL;

  struct record *mostrecentlycreated = firstrecord;

  const int cyes = 1;
  int iyes = 1;

  while (iyes == cyes)
  {    
      // build next node
      struct record *newrecord = (struct record *)malloc(sizeof(struct record));

      // change data in new record    
      newrecord->id = 1000   i;

      printf("Enter the name: ");
      fgets(newrecord->name, 257, stdin);
    
      printf("Enter the person's age: ");
      scanf("%f", &(newrecord->age));
    
      newrecord->next = NULL;

      mostrecentlycreated = newrecord;

        i;

      // decide whether or not to keep going
      printf("Do you wish to continue? 1\\0 ");
      scanf("%d", &iyes);
  }

  struct record *traverse = firstrecord;
  while (traverse != NULL)
  {
    printf("Employee id is %i; Employee Name is %s; Employee Age is %f\n", traverse->id, traverse->name, traverse->age);
    traverse = traverse->next;
  }

  traverse = firstrecord;
  while (traverse != NULL)
  {
    struct record *nextrecord = traverse->next;
    free(traverse);
    traverse = nextrecord;
  }

  return 0;
}

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