c语言 删除链表中第一个包含值的元素,补全一下我的这个代码

问题描述:

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

struct node {
struct node *next;
int data;
};

struct node *delete_contains(int value, struct node *head);
struct node *strings_to_list(int len, char *strings[]);
void print_list(struct node *head);

// DO NOT CHANGE THIS MAIN FUNCTION

int main(int argc, char *argv[]) {
int value;
scanf("%d", &value);
// create linked list from command line arguments
struct node *head = strings_to_list(argc - 1, &argv[1]);

struct node *new_head = delete_contains(value, head);
print_list(new_head);

return 0;

}

//
// Delete the first node in the list containing the value value.
// The deleted node is freed.
// If no node contains value, the list is not changed.
// The head of the list is returned.
//
struct node *delete_contains(int value, struct node *head) {

// PUT YOUR CODE HERE (change the next line!)
return NULL;

}

// DO NOT CHANGE THIS FUNCTION
// create linked list from array of strings
struct node *strings_to_list(int len, char *strings[]) {
struct node *head = NULL;
int i = len - 1;
while (i >= 0) {
struct node *n = malloc(sizeof (struct node));
assert(n != NULL);
n->next = head;
n->data = atoi(strings[i]);
head = n;
i -= 1;
}
return head;
}

// DO NOT CHANGE THIS FUNCTION
// print linked list
void print_list(struct node *head) {
printf("[");
struct node *n = head;
while (n != NULL) {
// If you're getting an error here,
// you have returned an invalid list
printf("%d", n->data);
if (n->next != NULL) {
printf(", ");
}
n = n->next;
}
printf("]\n");
}

struct node *delete_contains(int value, struct node *head) 
{
    if(head == NULL)
      return head;
    struct node *p = head;
    if(p->data == value)
        return p->next;
    struct node *q = p;
    p = p->next;
    while(p != NULL)
    {
          if(p->data == value)
          {
              q->next = p->next;
              break;
          }
          q = p;
          p = p->next;
    }
    return head;
}

用if判断一下不为空,

head->next =head->next ->next