无法反转链接列表 - c语言

我有一个简单的链接列表，每个节点中有一个字符串，int和下一个指针。无法反转链接列表 - c语言

所有其他链接列表函数的作品（弹出，推，删除节点等），但相反的功能只是复制我的节点。

这里是我的代码：

personNode* reverseList(personNode* head) 
    { 
     personNode* curr = head; 
     personNode* previous = NULL; 
     personNode* next = NULL; 

     while (curr != NULL) 
     { 
      next = curr->next; 
      curr->next = previous; 
      previous = curr; 
      curr = next; 
     } 

     head = previous; 
     printf("Line reversed!"); 

     return head; 
    }

结果是：

“逆转” 之前：
before

后：
after

（这里是整个代码:)

#include <stdio.h> 

#define STR_LEN 21 

typedef struct personNode 
{ 
    char name[STR_LEN]; 
    int age; 
    char friends[3][STR_LEN]; 
    struct personNode* next; 

}personNode; 

int recursiveLength(personNode* head, int counter); 
void createPerson(char name[], int age, char friends[3][STR_LEN], personNode* head); 
void link(personNode* head, personNode* toLink); 
char* iHaveFriends(personNode* guest, personNode* head); 
int addBehindFriend(char* friendName, personNode* guest, personNode* head); 
void removePersonByName(char name[], personNode* head); 
void addToListTop(personNode* VIP, personNode* head); 
void search(personNode* head, char name[]); 
personNode* reverseList(personNode* head); 
void freeList(personNode* head); 

int main(void) 
{ 
    int i = 0; 
    int choice = 0; 
    char name[STR_LEN] = { 0 }; 
    int age = 0; 
    char friends[3][STR_LEN]; 

    personNode* head = (personNode*)malloc(sizeof(personNode)); 
    head->next = NULL; 

    while (choice != 7) 
    { 
     printf("\n\nWelcome to MagshiParty Line Management Software!\nPlease enter your choice from the following options :\n1 - Print line\n2 - Add person to line\n3 - Remove person from line\n4 - VIP guest\n5 - Search in line\n6 - Reverse line\n7 - Exit\n"); 
     scanf("%d", &choice); 

     switch (choice) 
     { 
      case 1: 
      { 
       printf("%d people in line: \n", recursiveLength(head, 0)); 
       recursivePrint(head); 
       break; 
      } 

      case 2: 
      { 
       printf("Welcome guest!"); 
       printf("\nEnter name: "); 
       getchar(); 
       scanf("%[^\t\n]s", name); 
       getchar(); 

       printf("\nEnter age: "); 
       scanf("%d", &age); 

       printf("Enter names of 3 friends: "); 

       for (i = 0; i < 3; i++) 
       { 
        printf("\nFriend %d: ", i + 1); 
        getchar(); 
        scanf("%[^\t\n]s", friends[i]); 
        getchar(); 
       } 

       createPerson(name, age, friends, head); 
       break; 
      } 

      case 3: 
      { 
       printf("Enter name to remove: "); 
       getchar(); 
       scanf("%[^\t\n]s", name); 
       getchar(); 

       removePersonByName(name, head); 

       break; 
      } 

      case 4: 
      { 
       printf("VIP GUEST!\n"); 
       printf("Enter name: "); 
       getchar(); 
       scanf("%[^\t\n]s", name); 
       getchar(); 

       printf("Enter age: "); 
       scanf("%d", &age); 

       personNode* newNode = (personNode*)malloc(sizeof(personNode)); 

       newNode->age = age; 
       strcpy(newNode->name, name); 
       newNode->next = NULL; 

       addToListTop(newNode, head); 

       break; 
      } 

      case 5: 
      { 

       printf("Enter name to search: "); 
       getchar(); 
       scanf("%[^t\n]s", name); 
       getchar(); 

       search(head, name); 

       break; 
      } 

      case 6: 
      { 
       head = reverseList(head); 
       break; 
      } 

      case 7: 
      { 
       freeList(head); 
       printf("Goodbye!"); 
       break; 
      } 

      default: 
      { 
       freeList(head); 
       printf("Goodbye!"); 
       break; 
      } 
     } 
    } 

    getchar(); 
    getchar(); 
    return 0; 
} 

int recursiveLength(personNode* head, int counter) 
{ 
    personNode* curr = head; 
    if (head->next == NULL) 
    { 
     return counter; 
    } 
    else 
    { 
     if (curr->next != NULL) 
     { 
      counter++; 
      recursiveLength(curr->next, counter); 
     } 
     else 
     { 
      return counter; 
     } 
    } 
} 

int recursivePrint(personNode* head) 
{ 
    personNode* curr = head; 
    if (head->next == NULL) 
    { 
     return 0; 
    } 
    else 
    { 
     if (curr->next != NULL) 
     { 
      printf("Name: %s, Age: %d \n", curr->name, curr->age); 
      recursivePrint(curr->next); 
     } 
     else 
     { 
      return 0; 
     } 
    } 
} 

void createPerson(char name[], int age, char friends[3][STR_LEN], personNode* head) 
{ 
    int i = 0; 
    personNode* newNode = (personNode*)malloc(sizeof(personNode)); 

    for (i = 0; i < 3; i++) 
    { 
     strcpy((newNode->friends[i]), friends[i]); 
     //printf("inserted = %s , bimkom - %s\n", (newNode->friends[i]), friends[i]); 
    } 

    newNode->age = age; 
    strcpy(newNode->name, name); 
    newNode->next = NULL; 

    link(head, newNode); 
} 

void link(personNode* head, personNode* toLink) 
{ 
    personNode* curr = head; 
    int i = 0; 

    if (head->next == NULL) // first node - list empty 
    { 
     //printf("First!"); 
     for (i = 0; i < 3; i++) 
     { 
      strcpy((head->friends[i]), (toLink->friends[i])); 
      //printf("inserted = %s , bimkom - %s\n", (head->friends[i]), toLink->friends[i]); 
     } 
     //curr->next = malloc(sizeof(personNode)); 
     curr->age = toLink->age; 
     strcpy(curr->name, toLink->name); 
     head->next = toLink; 
     //curr->next = NULL; 
    } 
    else 
    { 
     char foundFriend[STR_LEN] = { 0 }; 
     strcpy(foundFriend, iHaveFriends(toLink, head)); 
     //printf("returned from iHaveFriends: %s", foundFriend); 

     if (!addBehindFriend(foundFriend, toLink, head)) 
     { 
      //printf("addBehindFriend Failed!"); 
      while (curr->next != NULL) 
      { 
       curr = curr->next; 
      } 
      //curr->next = malloc(sizeof(personNode)); 
      for (i = 0; i < 3; i++) 
      { 
       *(head->friends[i]) = toLink->friends[i]; 
      } 
      curr->age = toLink->age; 
      strcpy(curr->name, toLink->name); 
      curr->next = toLink; 
     } 
    } 
} 

char* iHaveFriends(personNode* guest, personNode* head) 
{ 
    personNode* curr = head; 
    int i = 0; 
    char foundFriend[STR_LEN] = { 0 }; 

    while (curr->next != NULL) 
    { 
     for (i = 0; i < 3; i++) 
     { 
      if (strcmp(curr->name, guest->friends[i]) == 0) 
      { 
       //printf("\nMATCH: %s, %s, %s\n", foundFriend, guest->friends[i], curr->name); 
       strcpy(foundFriend, guest->friends[i]); 
      } 
      else 
      { 
       //printf("\nProblem in friend Check!, compared: %s, %s\n", curr->name, guest->friends[i]); 
      } 
     } 
     //printf("\nName: %s", curr->name); 
     curr = curr->next; 
    } 
    //printf("\nReturning: %s", foundFriend); 
    return foundFriend; 
} 

int addBehindFriend(char* friendName, personNode* guest, personNode* head) 
{ 
    //printf("\nrecived: %s, %s\n", friendName, guest->name); 
    personNode* curr = head; 
    personNode* temp = 0; 
    char foundFriend[STR_LEN] = { 0 }; 
    int flag = 0; 
    while (curr->next != NULL) 
    { 
     if (strcmp(friendName, curr->next->name) == 0) 
     { 
      flag = 1; 
      temp = curr->next; 
      curr->next = guest; 
      guest->next = temp; 
     } 
     else 
     { 
      //printf("%s, %s\n", friendName, curr->next->name); 
     } 
     curr = curr->next; 
    } 
    return flag; 
} 

void removePersonByName(char name[], personNode* head) 
{ 
    personNode* curr = head; 
    int flag = 0; 

    while (curr->next != NULL) 
    { 
     if (strcmp(curr->next->name, name) == 0 && curr->next->next != NULL) 
     { 
      flag = 1; 
      curr->next = curr->next->next; 
      break; 
     } 
     curr = curr->next; 
    } 

    if (flag) 
    { 
     printf("%s removed from line", name); 
    } 
    else 
    { 
     printf("%s not in line", name); 
    } 
} 

void addToListTop(personNode* VIP, personNode* head) 
{ 
    personNode* tmp = (personNode*)(malloc(sizeof(personNode))); 

    tmp->age = head->age; 
    strcpy(tmp->name, head->name); 
    tmp->next = head->next; 

    head->age = VIP->age; 
    strcpy(head->name, VIP->name); 
    head->next = tmp; 

    //VIP->next = tmp; 
} 

void search(personNode* head, char name[]) 
{ 
    personNode* curr = head; 
    int flag = 0; 

    while (curr->next != NULL) 
    { 
     if (strcmp(curr->name, name) == 0) 
     { 
      flag = 1; 
      break; 
     } 
     curr = curr->next; 
    } 

    if (flag) 
    { 
     printf("%s found in line", name); 
    } 
    else 
    { 
     printf("%s not in line", name); 
    } 

} 

personNode* reverseList(personNode* head) 
{ 
    personNode* curr = head; 
    personNode* previous = NULL; 
    personNode* next = NULL; 

    while (curr != NULL) 
    { 
     next = curr->next; 
     curr->next = previous; 
     previous = curr; 
     curr = next; 
    } 

    head = previous; 
    printf("Line reversed!"); 

    return head; 
}

来源

2017-06-13 yossef douieb

+10

，我只是想了解为什么如此多的人更倾向于采取截图，裁剪，上传，在后插入它，而不是选择 - > CTRL + C-> CTRL + V –

你的逆转逻辑看起来是正确的。我敢说这个问题在别处。 – StoryTeller

你忘了'#include '和'#include '。 –

你的反向函数逻辑看起来很好。有没有在你的recursiveprint功能的问题，所以在这里你走，试试这个简单的一个：

void print(struct personNode *head) 
{ 
    struct personNode *temp = head; 
    while(temp != NULL) 

    { 
        printf("%s  ", temp->name);    
        temp = temp->next;  
    } 
}

来源

2017-06-13 09:09:22

@MukarramPasha一般提示：不要复制现有的代码，只需写一点评论（“你的功能，就像是，工作正常，也许[...]”）。 – Aconcagua

反向功能不能正常工作，因为它应该在我的本地机器上。

这很难调试它，所以我最好重写它。

反向功能的工作原理是这样的：

static personNode * reverse(struct personNode *head) 
{ 
    struct personNode* localHead = NULL; 
    struct personNode* temp; 
    struct personNode* remainingHead; 

    while (head != NULL) 
    { 
     remainingHead = head->next; 

     temp = localHead; 
     localHead = head; 
     localHead->next = temp; 

     head = remainingHead; 
    } 
    return localHead; 
}

关于递归的youre打印功能

我检查了头空，而不是下一个指针。

int recursivePrint(personNode* head) 
{ 
    personNode* curr = head; 
    if (head == NULL) 
    { 
     return 0; 
    } 
    else 
    { 
     if (curr != NULL) 
     { 
      printf("Name: %s, Age: %d \n", curr->name, curr->age); 
      recursivePrint(curr->next); 
     } 
     else 
     { 
      return 0; 
     } 
    } 
}

来源

2017-06-13 10:20:19 doremifasolasido

无法反转链接列表 - c语言

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