我在C ++中的Trie程序存在逻辑错误

Question

我正在尝试使用Linkedlist和Arrays在C ++中实现Trie，但它有一些我无法追踪的逻辑错误。从程序中，我希望将字符串作为输入用于插入和结束输入模式，我提供了＃＆＃39;＃＆＃39;字符。 它转移到搜索模式，但每个查询都打印＆＃34;未找到＆＃34;。 我正在使用编译器VC12 - Visual Studio 2013社区。

#include <iostream>
#include <string>
#include <cctype>

using namespace std;

enum state{
    acceptable, na
};
class TrieNode{
    void setNULL(){
        for (int i = 0; i < 26; i++)
        {
            next[i] = NULL;
        }
    }
public:
    state s;
    TrieNode *next[26];

    TrieNode(){
        setNULL();
        s = na;
    }
    TrieNode(state s){
        this->s = s;
        setNULL();
    }
    TrieNode *&goNext(char ch){
        ch = tolower(ch);
        return next[ch - 'a'];
    }
};
class Trie{
    TrieNode *head[26];
    void setNULL(){
        for (int i = 0; i < 26; i++)
        {
            head[i] = NULL;
        }
    }
public:
    Trie(){
        setNULL();
    }
    void insert(string &s){
        TrieNode *ptr = head[s[0] - 'a'];

        if (ptr == NULL){
            ptr = new TrieNode();
        }

        int i = 1;
        while (i < s.length())
        {
            if (ptr->goNext(s[i]) == NULL){
                ptr->goNext(s[i]) = new TrieNode();
            }
            ptr = ptr->goNext(s[i]);

            i++;
        }

        ptr->s = acceptable;
    }
    bool search(string &s){
        TrieNode *ptr = head[s[0] - 'a'];

        int i = 1;
        bool found = true;

        while (i < s.length() && found){
            if (ptr == NULL || ptr->goNext(s[i]) == NULL)
                found = false;
            else
                ptr = ptr->goNext(s[i]);
        }

        if (found == true)
            return true;
        return false;
    }
};

int main(){
    Trie t;

    string s;
    while (cin >> s, s != "#"){
        t.insert(s);
    }

    cout << "Search mode\n";

    while (cin >> s, s != "#"){
        if (t.search(s))
            cout << "Found\n";
        else
            cout << "Not found\n";
    }

    /*
    Sample Input:


    hello
    how
    are
    you
    #
    hello

    */

    return 0;
}

Answer 1

修改后的最终计划。谢谢大家的帮助。

#include <iostream>
#include <string>
#include <cctype>
#include <iomanip>

using namespace std;

enum state{
    acceptable, na
};
class TrieNode{
    void setNULL(){
        for (int i = 0; i < 26; i++)
        {
            next[i] = NULL;
        }
    }
public:
    state s;
    TrieNode *next[26];

    TrieNode(){
        setNULL();
        s = na;
    }
    TrieNode(state s){
        this->s = s;
        setNULL();
    }
    TrieNode *&goNext(char ch){
        ch = tolower(ch);
        return next[ch - 'a'];
    }
};
class Trie{
    TrieNode *head[26];
    void setNULL(){
        for (int i = 0; i < 26; i++)
        {
            head[i] = NULL;
        }
    }
public:
    Trie(){
        setNULL();
    }
    void insert(string &s){
        TrieNode *ptr = head[s[0] - 'a'];

        if (ptr == NULL){
            ptr = new TrieNode();
            head[s[0] - 'a'] = ptr;
        }

        int i = 1;
        while (i < s.length())
        {
            if (ptr->goNext(s[i]) == NULL){
                ptr->goNext(s[i]) = new TrieNode();
            }
            ptr = ptr->goNext(s[i]);

            i++;
        }

        ptr->s = acceptable;
    }
    bool search(string &s){
        TrieNode *ptr = head[s[0] - 'a'];

        if (ptr == NULL)
            return false;

        int i = 1;
        bool found = true;

        while (i < s.length() && found){
            if (ptr == NULL || ptr->goNext(s[i]) == NULL)
                found = false;
            else
                ptr = ptr->goNext(s[i]);

            i++;
        }

        if (ptr->s == acceptable)
            return found;
        return false;
    }
};

int main(){
    Trie t;

    cout << "Note : Only small characters are acceptable\n";

    string s;
    while (cin >> s, s != "#"){
        t.insert(s);
    }

    cout << "Search mode\n";

    while (cin >> s, s != "#"){
        if (t.search(s))
            cout << setw(20) << "Found\n";
        else
            cout << setw(20) << "Not found\n";
    }

    /*
    Sample Input:


    hello
    how
    are
    you
    #
    hello

    */

    return 0;
}