左神算法学习日记——前缀树

前缀树的实现 

#include<iostream>
#include<string>
#include<vector>
#include<hash_map>
#include<hash_set>
using namespace std;

class node
{
public:
	int pass;
	int end;
	hash_map<char,node*> edge;
	node() = default;
};

class tree
{
private:
	node* root;
public:
	tree()
	{
		root = new node();
	}
	void insert(string word)
	{
		node* temp = root;
		for (char var : word)
		{
			if (temp->edge.find(var) == temp->edge.end())
			{
				temp->edge.insert({ var,new node() });
			}
			temp = temp->edge[var];
			temp->pass++;
		}
		temp->end++;
	}
	int search(string word)
	{
		node* temp = root;
		for (char var : word)
		{
			if (temp->edge.find(var) == temp->edge.end())
			{
				return 0;
			}
			temp = temp->edge[var];
		}
		return temp->end;
	}
	void Delete(string word)
	{
		if (search(word))
		{
			node* temp = root;
			for (char var : word)
			{
				if (--temp->edge[var]->pass==0)
				{
					delete temp->edge[var];
					return;
				}
				temp = temp->edge[var];
			}
			temp->end--;
		}
	}
};