C 语言单链表的实现（简单实现）

简单的实现单链表的增删遍历操作，还有一些功能需要实现。我感觉难理解的时候画图来搞清楚逻辑，先画个图比划就行。

// @author:Gong
// @single Linked list
// @ 增、删、遍历
#include<stdio.h>
#include<stdlib.h>
/*从新定义节点的数据域数据类型，以后好修改具体的链表*/
typedef int Data_type;

typedef struct Node* Node_p;
/*定义一个链表的节点结构体，关键有数据域和指针域*/
struct Node{
	Data_type data;
	struct Node* next;
};


/*创建一个链表，关键是创建一个头节点*/
Node_p create_list(){
	Node_p list = (Node_p)malloc(sizeof(struct Node));
	list->next = NULL;
	return list;
}
/*创建一个链表的节点，也就是开辟一个内存空间存储节点的数据*/
Node_p create_list_node(Data_type  data){
	Node_p new_node = malloc(sizeof(struct Node));
	new_node->data = data;
	return new_node;
}
/*在链表的头部增加值*/
void insert_node_by_head(Node_p list, Data_type  data){
	Node_p  new_node = create_list_node(data);
	new_node->next = list->next;
	list->next = new_node;
}

/*在链表的尾部增加值*/
void insert_node_by_last(Node_p list, Data_type data){
	Node_p new_node = create_list_node(data);
	Node_p ptr = list->next;
	while (ptr->next != NULL){
		ptr = ptr->next;
	}
	ptr->next = new_node;
	new_node->next = NULL;
}	

/*在链表的指定位置增加值*/
void insert_node_by_pos(Node_p list, Data_type data,Data_type pos){
	Node_p new_node = create_list_node(data);
	Node_p before_node = list;
	Node_p after_node=list->next;
	while (after_node->data != pos){
		before_node = after_node;
		after_node = before_node->next;
		if (after_node == NULL){
			printf("NOT FIND THE POSITION TO INSERT!\n");
		}
	}
	new_node->next = after_node;
	before_node->next = new_node;
}

/*在链表的指定参数位置删除，这里只是以值来判断*/
void delete_node_by_pos(Node_p list, Data_type pos){
	Node_p before_node=list;
	Node_p after_node = list->next;
	while (after_node->data != pos){
		before_node = after_node;
		after_node=after_node->next;
		if (after_node == NULL){
			printf("Not find the positon to delete node!\n");
		}
	}
	before_node->next = after_node->next;
	free(after_node);

}
/*在链表的头部删除*/
Node_p delete_node_by_head(Node_p list){
	Node_p temp_node = list->next;
	list->next = temp_node->next;
	
	return temp_node;
}
/*打印链表的具体值，遍历操作*/
void print_list(Node_p list){
	Node_p ptr = list->next;
	while (ptr!= NULL){
		printf("%d\t", ptr->data);
		ptr = ptr->next;
	}
	printf("\n");
}

int main(void){
	Node_p List = create_list();
	insert_node_by_head(List, 1);
	insert_node_by_head(List, 2);
	insert_node_by_head(List, 3);
	insert_node_by_head(List, 4);
	insert_node_by_head(List, 5);
	insert_node_by_last(List, 6);
	insert_node_by_pos(List, 100, 6);
	insert_node_by_pos(List, 200, 6);
	print_list(List);
	delete_node_by_pos(List, 200);  // 没有返回被删的节点
	print_list(List);
	Node_p p= delete_node_by_head(List); // 返回被删的节点
	printf("Not be free:%d\n",p->data);
	free(p);
	print_list(List);
	while (1);
}