The Trie data structure

[reflect29]

I'm trying to digest the code from this site:
https://www.techiedelight.com/cpp-implementation-trie-data-structure/

I'm currently stuck near the beginning:

#include <iostream>
using namespace std;
 
// Define the character size
#define CHAR_SIZE 128
 
// A class to store a Trie node
class Trie
{
public:
    bool isLeaf;
    Trie* character[CHAR_SIZE];
 
    // Constructor
    Trie()
    {
        this->isLeaf = false;
 
        for (int i = 0; i < CHAR_SIZE; i++) {
            this->character[i] = nullptr;
        }
    }
 
    void insert(string);
    bool deletion(Trie*&, string);
    bool search(string);
    bool haveChildren(Trie const*);
};

Can someone please confirm what this line does:
Trie* character[CHAR_SIZE];

Does this mean each object of the Trie class, will have an array of 128 pointers to other Trie objects?

[jonnin]

yes, it means that each one can potentially have 0 to 128 children.

[seeplus]

Note that if you initialise the variables when defined, the constructor can be vastly simplified:

#include <iostream>
using namespace std;

// Define the character size
constexpr size_t CHAR_SIZE {128};

// A class to store a Trie node
class Trie {
public:
	bool isLeaf {};
	Trie* character[CHAR_SIZE] {};

	// Constructor
	Trie() {}

	void insert(const string&);
	bool deletion(Trie*&, const string&);
	bool search(const string&);
	bool haveChildren(Trie const*);
};

You also need a destructor, a copy constructor (and preferably also a move constructor) and an assignment (operator=) function.

Note that that code has issues.

[thmm]

Note that that code has issues.

Politely said, many other people would call it crap.

Another good example why people shouldn't search for C++ code on the net.

[jonnin]

in the page's view source: datePublished":"2016-12-03T04:24:19+00:00"
probably best to not study too much code written before 2018 as a rough ballpark.