C语言单链表的总结

文章目录

• • 初始节点结构：
  • 建链：
  • 插入：
  • • 尾插法：
    • 头插法：
  • 打印链表：
  • 删除节点：
  • 反转链表：
  • • 迭代法：
    • 递归法：
  • 一个完整代码（含输入输出）：

初始节点结构：

struct ListNode {
	int val;
	struct ListNode *next;
}

建链：

struct ListNode* createlist() {
	struct ListNode* Hnode = (struct ListNode*)malloc(sizeof(struct ListNode));
	Hnode -> next = NULL;
	return Hnode;
}

插入：

尾插法：

struct ListNode* insertNode(struct ListNode* list, int num); {
	int i;
	struct ListNode* tail = list;
	for(i = 0; i < n; i++) {
		struct ListNode* node = (struct ListNode*)malloc(sizeof(struct ListNode));
		scanf("%d", &node -> val);
		tail -> next = node;
		tail = tail -> next;
	}
	return list;
}

头插法：

struct ListNode* insertNode(struct ListNode* list, int num); {
	int i;
	struct ListNode* tail = list;
	for(i = 0; i < n; i++) {
		struct ListNode* node = (struct ListNode*)malloc(sizeof(struct ListNode));
		scanf("%d", &node -> val);
		node -> next = list -> next;
		list -> next = node;
	}
	return list;
}

打印链表：

void printList(struct ListNode* list) {
	struct ListNode* p = list -> next;
	
	while(p) {
		printf("%d ",p -> val);
		p = p->next;
	}
}

删除节点：

struct ListNode* deleteList(struct ListNode* head, int val) {
	struct ListNode* prev = (struct ListNode*)malloc(sizeof(struct ListNode));
	prev -> next = head;
	struct ListNode* p = prev;
	while(prev != NULL && prev -> next != NULL) {
		if(prev -> next -> val == val) {
			prev -> next = prev -> next -> next;
		} else {
			prev = prev -> next;
		}
	}
	return p -> next;
}

反转链表：

迭代法：

struct ListNode* reverseList(struct ListNode* head){
    struct ListNode* prev=NULL;
    struct ListNode* curr=head;
    while(curr){
        struct ListNode* next=curr->next;
        curr->next=prev;
        prev=curr;
        curr=next;
    }
    return prev;
}

递归法：

struct ListNode* reverseList(struct ListNode* head) {
    if (head == NULL || head->next == NULL) {
        return head;
    }
    struct ListNode* newHead = reverseList(head -> next);
    head -> next -> next = head;
    head -> next = NULL;
    return newHead;
}

一个完整代码（含输入输出）：

#include<stdio.h>
#include<stdlib.h>
struct ListNode
{
	int val;
	struct ListNode* next;	
};


struct ListNode* createlist()
{
	struct ListNode* Hnode = (struct ListNode*)malloc(sizeof(struct ListNode));
	Hnode -> next = NULL;
	return Hnode;
}

struct ListNode* insertNode(struct ListNode* list, int num) {
	int i;
	struct ListNode* tail = list;
	for(i = 0; i < num; i++) {
		struct ListNode* node = (struct ListNode*)malloc(sizeof(struct ListNode));
		scanf("%d", &node -> val);
		node -> next = list -> next;
		list -> next = node;
	}
	return list;
}



void printlist(struct ListNode* list) {

	struct ListNode* p = list -> next;
	
	while(p) {
		printf("%d ",p -> val);
		p = p->next;
	}
}
struct ListNode* deleteList(struct ListNode* head, int val) {
	struct ListNode* prev = (struct ListNode*)malloc(sizeof(struct ListNode));
	prev -> next = head;
	struct ListNode* p = prev;
	while(prev != NULL && prev -> next != NULL) {
		if(prev -> next -> val == val) {
			prev -> next = prev -> next -> next;
		} else {
			prev = prev -> next;
		}
	}
	return p -> next;
}

int main(void)
{
	struct ListNode* list,* list1;
	int num;
	scanf("%d", &num);
	list = createlist();
	list1 = insertNode(list, num);
	printlist(list1);
	deleteList(list1, 3);
	printf("\n");
	printlist(list1);
	return 0;
}

输入：
5
1 3 5 7 9
（deleteList函数，删除val：3）
输出：