99.链表经典题

前提

#include <stdio.h>
#include <stdlib.h>
struct Node {
    int data;
    struct Node* next;
};
typedef struct Node node;
void printList(struct Node* n)
{
    while(n != NULL) {
        printf(" %d ", n->data);
        n = n->next;
    }
    puts("");
}
void appendToArray(node** head_ref, int* a, int len)
{
    if (len <= 0) {
        printf("the given len must be greater than or equal to 0");
        return ;
    }
    if (*head_ref != NULL) {
        printf("please input a linked list for empty");
        return ;
    }
    node* temp = (node*)malloc(sizeof(node));
    *head_ref = temp;
    temp->data = a[0];
    temp->next = NULL;
    for(int i=1; i<len; ++i) {
        node *new_node = (node*)malloc(sizeof(node));
        new_node->data = a[i];
        new_node->next = NULL;
        temp->next = new_node;
        temp = new_node;
    }
}

单链表反转

void reverselinkedlist(node** head_ref)
{
    node* pre = null;
    node* current = *head_ref;
    node* next = current->next;
    while(current != null) {
        next = current->next;
        current->next = pre;
        pre = current;
        current = next;
    }
    *head_ref = pre;
}
int main()
{
    node* head = NULL;
    int a[5] = {1, 2, 3, 4, 5};
    appendToArray(&head, a, 5);
    printList(head);
    reverseLinkedList(&head);
    printList(head);
}

链表中环的检测

两个有序的链表合并

递归的写法更好

删除链表倒数第 n 个结点

111.删除链表倒数第 n 个结点.md

求链表的中间结点