我的鏈表中的分段錯誤錯誤-C

Question

我把幾段代碼放在一起做一個鏈接列表，添加到頭部（有一個特殊功能）和中間（也有特殊功能）。 我的問題是，我需要提供數字程序並將它們作爲節點插入到我的LINKEDLIST中。但是，我的顯示功能（顯示節點樹）給出了分段錯誤，因此只是在沒有任何顯示功能的情況下取值。 我對malloc相當陌生，所以我懷疑問題在那裏？ 謝謝

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

/*LINKEDLIST STRUCT*/ 
struct node { 
     int data; 
     struct node *next; 
     }; 
    /*Inserting head-Node*/ 
struct node *insert_head(struct node *head, int number) 
{ 
    struct node *temp; 
    temp = malloc(sizeof(struct node)); 
    if(temp == NULL) 
    { 
     printf("Not enough memory\n"); 
     exit(1); 
    } 

    temp->data = number; 
    temp->next = head; 
    head = temp; 
    return head; 

} 
    /*Inserting inside a list*/ 
void after_me(struct node *me, int number) 
{ 
    struct node *temp; 
    temp = malloc(sizeof(struct node)); 
    if(temp == NULL) 
    { 
     printf("Not enough memory\n"); 
     exit(1); 
    } 

    temp->data = number; 

    temp->next = me->next; 
    me->next = temp; 
} 
    /*PRINTING LIST*/ 
void display(struct node *head) 
{ 
    struct node *moving_ptr = head; 
    while(moving_ptr != NULL) 
    { 
     printf("%d-->",moving_ptr->data); 
     moving_ptr = moving_ptr->next; 
    } 
} 
int main() 
{ 
    int index; 
    struct node *head; 
    struct node *previous_node; 

    scanf("%d", &index); 
    while(index > 0) 
    { 


     /*allocating in List */ 
     if(head == NULL) 
      head = insert_head(head,index); 
     else 
     if((head != NULL) && (index <= (head->data))) 
      { 
       struct node *temp; 
       head->next = temp; 
       temp->next = head;/*TRY INSERT HEAD FUNC.*/ 
      } 
     else 
     if((head != NULL) && (index > (head->data))) 
     { 
      previous_node->data = index-1; 
      after_me(previous_node,index); 
     } 

     scanf("%d", &index); 

    } 

     display(head); 




} 

Answer 1

我建議如下。

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

struct node { 
    int data; 
    struct node *next; 
}; 
//aggregated into one place  
struct node *new_node(int number){ 
    struct node *temp; 
    if(NULL == (temp = malloc(sizeof(*temp)))){ 
     printf("\nNot enough memory\n"); 
     exit(1); 
    } 
    temp->data = number; 
    temp->next = NULL; 
    return temp; 
} 

struct node *insert_head(struct node *head, int number) { 
    struct node *temp = new_node(number); 

    temp->next = head; 
    return temp; 
} 

void after_me(struct node *me, int number){ 
    struct node *temp = new_node(number); 

    temp->next = me->next; 
    me->next = temp; 
} 
void display(struct node *head){ 
    struct node *moving_ptr = head; 
    while(moving_ptr != NULL){ 
     printf("%d", moving_ptr->data); 
     if(moving_ptr = moving_ptr->next) 
      printf("-->"); 
    } 
    putchar('\n'); 
} 

struct node *insert(struct node *me, int number){ 
    if(me){ 
     if(number <= me->data){ 
      me = insert_head(me, number); 
     } else { 
      me->next = insert(me->next, number); 
     } 
    } else { 
     me = new_node(number); 
    } 
    return me; 
} 

void release(struct node *list){//Of course, you will be able to replace a simple loop(e.g while-loop). 
    if(list){ 
     release(list->next); 
     free(list); 
    } 
} 

int main(void){ 
    struct node *head = NULL; 
    int index; 

    while(1==scanf("%d", &index) && index > 0){ 
     head = insert(head, index); 
    } 
    display(head); 
    release(head); 
    return 0; 
}