电子小字典

// @author: Folivora Li
// @copyright: Folivora Li/*24、【3】电子小字典（选做）（查找）
[问题描述]
利用键树结构，建立一个微型电子字典。
[基本要求]
实现生词的加入，单词的查找、删除，修改等操作。*/
#include <iostream>
#include <string>
#include <map>
#include <vector>
#include <fstream>
using namespace std;
typedef struct treenode {char letter;bool IsWord = false;string meaning;treenode* next[26];
}Treenode;
void ReadFile(map<string, string>& dict)
{string word;string meaning;fstream file;file.open("D:\\dictionary.txt", ios::in);if (file.fail()){cout << "error!" << endl;exit(1);}while (!file.eof()){file >> word;file >> meaning;dict.insert(pair<string, string>(word, meaning));}
}
Treenode* InitTree()
{Treenode* root = new Treenode;for (int i = 0; i < 26; i++){root->next[i] = NULL;}return root;
}
int MapLetterToNum(char letter)
{return int(letter) - 97;
}
void Memset(Treenode* next[26])
{for (int i = 0; i < 26; i++){next[i] = NULL;}
}
void Insert(Treenode*& root, string word, string meaning)
{Treenode* p = root;int i = 0;for (i = 0; i < word.length(); i++){if (p->next[MapLetterToNum(word[i])] == NULL){p->next[MapLetterToNum(word[i])] = new Treenode;Memset(p->next[MapLetterToNum(word[i])]->next);p->next[MapLetterToNum(word[i])]->letter = word[i];p = p->next[MapLetterToNum(word[i])];}else{p = p->next[MapLetterToNum(word[i])];}}p->IsWord = true;p->meaning = meaning;
}
void Search(Treenode*& root, string word)
{Treenode* p = root;int i = 0;for (i = 0; i < word.length(); i++){if (p->next[MapLetterToNum(word[i])] == NULL){cout << "查找的单词不存在！" << endl;return;}else{p = p->next[MapLetterToNum(word[i])];}}cout << word << ":";cout << p->meaning << endl;
}
bool IsHaveBranch(Treenode* root, int serial)
{for (int i = 0; i < 26; i++){if (i != serial){if (root->next[i] != NULL){return true;}}}return false;
}
bool Delete(Treenode*& root, string word)
{Treenode* p = root;vector<Treenode*> word_vec;vector<Treenode*>::iterator iter;int i = 0;for (i = 0; i < word.length(); i++){if (p->next[MapLetterToNum(word[i])] == NULL){cout << "查找的单词不存在！" << endl;return false;}else{p = p->next[MapLetterToNum(word[i])];word_vec.push_back(p);}}Treenode* pre = NULL;for (iter=word_vec.end() - 1; iter != word_vec.begin(); iter--){pre = *(iter - 1);pre->next[MapLetterToNum((*iter)->letter)] = NULL;if (IsHaveBranch(pre, MapLetterToNum((*iter)->letter))){break;}}return true;
}
void Modify(Treenode*& root)
{cout << "请输入要修改的单词：" << endl;string wrongword;cin >> wrongword;cin.ignore();cout << "请输入修改后的单词：" << endl;string rightword;cin >> rightword;cin.ignore();cout << "请输入释义：" << endl;string meaning;cin >> meaning;cin.ignore();if (Delete(root, wrongword) == true){Insert(root, rightword, meaning);}
}
int main()
{map<string, string> dict;ReadFile(dict);Treenode* root = (InitTree());map<string, string>::iterator iter;int i = 0;for (iter = dict.begin(); iter != dict.end(); iter++,i++){Insert(root, iter->first, iter->second);}Search(root, "zinc");Search(root, "abandon");//Delete(root, "abandon");Modify(root);Search(root, "abandon");Search(root, "aaqw");
}