数据结构基础（三）哈希表的实现

#pragma once
#include <iostream>
#define N 10
using namespace  std;
typedef struct node
{
	int val;
	struct node *next;
}Node;
void freeLinklist(Node *&head);
void freeLinklist(Node *&head)
{
	if (head==NULL)
	{
		return;
	}
	if (head->next==NULL)
	{
		delete head;
		head=NULL;
		return;
	}
	Node *pre=head;
	Node *temp=head->next;
	while(temp->next!=NULL)
	{	delete pre;
		pre=temp;
		temp=temp->next;
	}
	delete pre;
	head=NULL;
};


class Hash
{
public:
	Hash()
	{
		for(int i=0;i<N;i++)
		{
			hashTable[i]=NULL;
		}
	};
~Hash()
{
	for (int i=0;i<N;i++)
	{
		freeLinklist(hashTable[i]);
	}
};
	Node* find(int val)
	{
		int index=val%N;
		Node *head=hashTable[index];
		if (head!=NULL)
		{
			while(head->next!=NULL&&head->val!=val)
			{
				head=head->next;
			}
			if (head->val==val)
			{
				return head;
			}
			return NULL;
		}
		return NULL;
	};

	Node* insert(int val)
	{
		int index=val%N;
		Node *head=hashTable[index];
		if (head!=NULL)
		{
			while(head->next!=NULL)
			{
				head=head->next;
			}
			head->next=new Node;
			head->next->val=val;
			head->next->next=NULL;
			return head->next;
		}
		head=new Node;
		head->next=NULL;
		head->val=val;
		hashTable[index]=head;
		return head;
	};
	void print()
	{
		for (int i=0;i<N;i++)
		{
			Node *head=hashTable[i];
			if(head==NULL)
			{
				cout<<endl;
				continue;
			}
			while(head->next!=NULL)
			{
				cout<<head->val<<"\t";
				head=head->next;
			}
			cout<<head->val<<endl;
			cout<<endl;
		}
	};
	bool deleteNode(int val)
	{
		Node *obj=find(val);
		if (obj==NULL)
		{
			return true;
		}
		//说明哈希表中有这个节点
 		Node *head=hashTable[val%N];
		if (head==obj)
		{
			hashTable[val%N]=obj->next;
			delete obj;
			deleteNode(val);
			return true;
		}
		while(head->next!=obj&&head->next!=NULL)
		{
			head=head->next;
		}
		head->next=obj->next;
		delete obj;
		deleteNode(val);
		return true;
	}

private:
	Node *hashTable[N];//这是个数组
};

这是哈希表的一种简单的基于数组的实现，哈希函数选为取余，对哈希表的操作就变成了对链表的操作