[数据结构]Trie

Posted 2022-12-05 yccy1230

//Trie.cpp
#include "Trie.h"
#pragma once

Trie_node::Trie_node()

	data = NULL;
	for (int i = 0; i<num_chars; i++)
		branch[i] = NULL;


Error_code Trie::insert(const Record & new_entry)

	Error_code result = success;
	if (root == NULL) root = new Trie_node;
	int position = 0; 
	char next_char;
	Trie_node *location = root; 
	while (location != NULL &&
		(next_char = new_entry.key_letter(position)) != '\\0') 
		int next_position = alphabetic_order(next_char);
		if (location->branch[next_position] == NULL)
			location->branch[next_position] = new Trie_node;
		location = location->branch[next_position];
		position++;
	
	if (location->data != NULL) result = duplicate_error;
	else location->data = new Record(new_entry);
	return result;


Error_code Trie::trie_search(const Key & target, Record & x) const

	int position = 0;
	char next_char;
	Trie_node *location = root;
	while (location != NULL &&
		(next_char = target.key_letter(position)) != '\\0') 
		location = location->branch[alphabetic_order(next_char)];
		position++;
	
	if (location != NULL && location->data != NULL) 
		x = *(location->data);
		return success;
	
	else
		return not_present;


Trie::Trie()

	root = NULL;


int alphabetic_order(char c)

	if (c == ' ' || c == '\\0') return 0;
	if ('a' <= c && c <= 'z') return c - 'a' + 1;
	if ('A' <= c && c <= 'Z') return c - 'A' + 1;
	return 27;

//Trie.h
#include "Record.h"
const int num_chars = 28;
enum Error_code  not_present, overflow, underflow, duplicate_error, success ;

struct Trie_node 
	Record * data;
	Trie_node * branch[num_chars];
	Trie_node();
;

class Trie 
public: 
	Error_code insert(const Record &new_entry);
	Error_code trie_search(const Key &target, Record &x) const;
	Trie();
private: 
	Trie_node *root;
;

int alphabetic_order(char c);

//Key
#include <iostream>
#include<string>
using namespace std;
const int key_size = 10;

class Key 
	char str[key_size];
public:
	Key(char s[]);
	char * the_key() const;
	char key_letter(int position) const;
;
#include "Key.h"

Key::Key(char s[]) 
	for (int i = 0; i <= strlen(s); i++)
		str[i] = s[i];


char * Key::the_key() const 
	return (char *)str;



char Key::key_letter(int position) const 
	if (position<strlen(str)) return str[position];
	else return '\\0';

//Record
#include "Key.h"
#include<string>
using namespace std;

class Record 
public:
	operator Key(); 
	Record(char s[] = "", string con="");
		char * the_key() const;
	char key_letter(int position) const;
private:
	char str[key_size];
	string content;
;

ostream & operator << (ostream &output, Record &x);
#include "Record.h"

Record::Record(char s[], string con) 
	for (int i = 0; i <= strlen(s); i++)
		str[i] = s[i];
	content = con;


Record::operator Key() 
	Key tmp(str);
	return tmp;

char Record::key_letter(int position) const 
	if (position<strlen(str)) return str[position];
	else return '\\0';


char * Record::the_key() const 
	return (char *)str;



ostream & operator << (ostream &output, Record &x)

	output << x.the_key();
	output << "  ";
	return output;