BinarySearchTreeString.cpp

#include <iostream>
#include<cstring>
#include <fstream>
class BinTreeNode
{
public:
    BinTreeNode(std::string value,int frecv)
    {
        this->value = value;
        this->frecv = frecv;
        this->left = NULL;
        this->right = NULL;
    }
    int frecv;
    std::string value;
    BinTreeNode* left;
    BinTreeNode* right;
};
BinTreeNode* tree_insert(BinTreeNode* tree, std::string word, int frecv)
{
    if (tree == NULL)
        tree = new BinTreeNode(word, frecv);
    else if (word<tree->value)
        if (tree->left == NULL)
            tree->left = new BinTreeNode(word, frecv);
        else
            tree_insert(tree->left, word, frecv);
    else if (tree->right == NULL)
        tree->right = new BinTreeNode(word, frecv);
    else
        tree_insert(tree->right, word, frecv);
    return tree;
}
void preorder(BinTreeNode* tree)
{
  std::cout << tree->value << ":"<<tree->frecv<<std::endl;
    if (tree->left != NULL)
        preorder(tree->left);
    if (tree->right != NULL)
        preorder(tree->right);
}
bool SearchNode(BinTreeNode* tree, std::string word)
{
    if(tree == NULL)
        return false;
    else if(tree->value == word)
        return true;
    else if(word <= tree->value)
        return SearchNode(tree->left,word);
    else return SearchNode(tree->right,word);
}
BinTreeNode* Frequency(BinTreeNode* tree, std::string word, int frecv)
{
    if(tree->value == word)
        tree->frecv=frecv+1;
    else if(word <= tree->value)
        return Frequency(tree->left,word, frecv);
    else return Frequency(tree->right,word, frecv);
    return tree;
}
int main()
{
    int frecv;
    std::string word;
    std::ifstream fin("paragraph.txt");
    fin>>word;
    BinTreeNode* t = tree_insert(0, word,1);
    while(fin>>word)
        if(SearchNode(t,word)==true)
            Frequency(t,word,frecv);
        else
        {
            frecv=1;
            tree_insert(t, word,frecv);
        }

    preorder(t);

    std::cout<<"Finding a word:";
    std::cin>>word;
    if(SearchNode(t,word)==true)
        std::cout<<"Yes"<<std::endl;
    else std::cout<<"No"<<std::endl;
    return 0;
}