Suffix tree insert and search

suff.cpp

#include <iostream>
#include <string>
#include <stdio.h>
#include <string.h>
using namespace std;

struct suffix_tree {
  std::string suffix;
  suffix_tree* child[26] = {};
  int index = 0;
  bool is_end = false;
};

suffix_tree* CreateNode() {
  suffix_tree* newnode = new suffix_tree();
  return newnode;
}

using node = suffix_tree;

string match(string a, string b) {
    size_t i = 0, j = 0;
    while (i < a.size() && j < b.size() && a[i] == b[j])
        i++, j++;
    return a.substr(0, i);
}

void Insert(node* head, string s) {
  node* current = head;
  for (size_t i = 0; i < s.size(); i++) {
    string word = s.substr(i);
    node** pChild = &current->child[word[0] - 'a'];
    if (*pChild == NULL) {
      *pChild = new node();
      (*pChild)->suffix = word;
      (*pChild)->is_end = true;
      (*pChild)->index = i;
    } else {
      string tmp = (*pChild)->suffix;
      if (word == tmp)
        return;
      string pre = match(word, tmp);
      (*pChild)->suffix = pre;
      
      if (i < word.size() - 1) {
        Insert(*pChild, word.substr(i + 1));
        (*pChild)->is_end = false; 
      }
      if (tmp.size() > 1) {
        Insert(*pChild, tmp.substr(1));
        (*pChild)->is_end = false; 
      }
    }
  }
}

bool Search(node* head, string word) {
  if (word.empty())
    return true;
  node* current = head;
  for (size_t i = 0; i < word.length();) {
    current = current->child[word[i] - 'a'];
    if (current == NULL)
      return false;

    size_t j = 0;
    //cout<<boolalpha<<((bool)current->child['b'-'a'])<<endl;
    for (; i < word.size() && j < current->suffix.size() &&
           word[i] == current->suffix[j];) {
      i++, j++;
    }
    
    if (i == word.size()) {
      cout << current->index << " ";
      return true;
    }
  }

  return true;
}

int main() {
  auto* root = new suffix_tree;
 
  string s = "abcbacl";
  string str = "acl"; 
  cout << s << "\n" << str << endl;
  Insert(root, s);
  
  if (Search(root, str) == true)
    cout << "Found\n";
  else
    cout << "Not found\n";
}