collection not returning anything

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collection not returning anything

collection not returning anything

Hello, I worked my code to read from a file and extract "<BODY>" and "</BODY>" tags but I intended to add "cout" to "std::string collection" just to see if it returns anything and it is not returning anything, can't seem to know why, if I run the function on it's own without adding it to a class it works fine, here is not returning anything. Help is appreciated :D

  #include <iostream>
#include <string>
#include <fstream>

using namespace std; 

struct TrieNode
{
	bool isEnd; 
	int HeapIndex; 
	TrieNode* child[26]; 
	int frequency; 
	TrieNode()
	{
		HeapIndex = -1; 
		isEnd = false; 
		frequency = 0; 
		for (int i = 0; i < 26; i++)
		{
			child[i] = NULL; 
		}
	}
};

struct HeapNode
{
	string word; 
	int frequency; 
	TrieNode* TN; 
	HeapNode()
	{
		frequency = 0; 
		TN = nullptr; 
		word = ""; 
	}
};

class Trie
{
private: 
	TrieNode* root; 
public: 
	Trie(); 
	
	TrieNode* insert(string word); 
	TrieNode* search(string word); 
};

Trie::Trie()
{
	root = new TrieNode(); 
}

TrieNode* Trie::insert(string word)
{
	TrieNode* temp = root; 
	for (unsigned int i = 0; i < word.length(); i++)
	{
		if (temp->child[word[i] - 'a'] == 0)
		{
			if (temp->child[word[i] - 'a'] == NULL)
			{
				TrieNode* node = new TrieNode();
				temp->child[word[i] - 'a'] = node;
			}
			temp = temp->child[word[i] - 'a'];
		}
	}
	temp->frequency = 1; 
	temp->isEnd = 1; 
	return temp; 
}

TrieNode* Trie::search(string word)
{
	TrieNode* temp = root; 
	for (unsigned int i = 0; i < word.length(); i++)
	{
		if (temp->child[word[i] - 'a'] == NULL)
		{
			return NULL; 
			temp = temp->child[word[i] - 'a']; 
		}
	}
	if (temp->isEnd)
	{
		return temp; 
	}
	else
	{
		return NULL; 
	}
}

class MinHeap
{
private: 
	int capacity, count; 
	HeapNode* array; 
public: 
	MinHeap() = default; 
	MinHeap(int capacity); 
	void Display(); 
	void minHeapify(int index); 
	void Build(int index); 
	void insert(TrieNode* TN, string word); 
	void TopKFrequentWord(string fileName, int k);
	string ExtractBodyNoTags(const string& text, string tag);
	void stripTags(string& text); 

	
};


MinHeap::MinHeap(int capacity)
{
	this->capacity = capacity; 
	count = 0; 
	array = new HeapNode[capacity]; 
}

void MinHeap::Display()
{
	for (int i = 0; i < capacity; i++)
	{
		cout << array[i].word << "  " << array[i].frequency << endl; 
	}
}

void MinHeap::minHeapify(int index)
{
	int left = 2 * index + 1; 
	int right = 2 * index + 2; 
	int minIndex = index; 
	if (left < count && array[left].frequency < array[minIndex].frequency)
	{
		minIndex = left; 
	}
	else if (right < count && array[right].frequency < array[minIndex].frequency)
	{
		minIndex = right; 
	}
	else if (minIndex != index)
	{
		array[index].TN->HeapIndex = minIndex; 
		array[minIndex].TN->HeapIndex = index;
		swap(array[index], array[minIndex]); 
		minHeapify(minIndex); 
	}
}

void MinHeap::Build(int index)
{
	int n = count - 1; 
	for (int i = (n - 1) / 2; i >= 0; i--)
	{
		minHeapify(i); 
	}
}

void MinHeap::insert(TrieNode* TN, string word)
{
	if (TN->HeapIndex != -1)
	{
		array[TN->HeapIndex].frequency++; 
		minHeapify(TN->HeapIndex); 
	}
	else if (count < capacity)
	{
		array[count].word = word; 
		array[count].frequency = 1;
		array[count].TN = TN; 
		TN->HeapIndex = count; 
		count++; 
		Build(count); 
	}
	else if (TN->frequency > array[0].frequency)
	{
		array[0].TN->HeapIndex = -1; 
		array[0].word = word; 
		array[0].frequency = TN->frequency; 
		array[0].TN = TN; 
		TN->HeapIndex = 0; 
		minHeapify(0); 
	}
}

void MinHeap::TopKFrequentWord(string fileName, int k)
{
	
	MinHeap mh(k);
	Trie T;
	string word;

	TrieNode* TN = T.search(word);
	if (!TN)
	{
		TN = T.insert(word);
	}
	else
	{
		TN->frequency++;
	}
	mh.insert(TN, word);

	mh.Display();
}




string MinHeap::ExtractBodyNoTags(const string& text, string tag)
{
	string collection;
	
	unsigned int pos = 0, start;

	while (true)
	{
		start = text.find("<" + tag, pos);
		if (start == string::npos) return collection;
		start = text.find(">", start);
		start++;

		pos = text.find("</" + tag, start);
		if (pos == string::npos) return collection;
		collection = text.substr(start, pos - start);
		cout << collection; 
	}
}

void MinHeap::stripTags(string& text)
{
	string body;
	unsigned int start = 0, pos;
	while (start < text.size())
	{
		start = text.find("<", start);
		if (start == string::npos)
		{
			break;
		}
		pos = text.find(">", start);
		if (pos == string::npos)
		{
			break;
		}
		
		body = text.substr(pos, start);
		
	}
}


int main()
{
	int k = 10; 
	string file;
	MinHeap mh(k);
	Trie T;
	string word;
	MinHeap foo; 
	string tag = "BODY"; 
	
	string stopword;
	ifstream in("C:\\Users\\Kareem's Laptop\\Desktop\\Reuters-21578\\reut2-000.sgm");
	if (!in.is_open())
	{
		cerr << "FILE NOT FOUND!" << endl; 
		exit(1); 
	}
	if (in.is_open())
	{
		while (!in.eof())
		{
			while (in >> word)
			{

				//foo.ExtractBodyNoTags(word, tag);

				TrieNode* TN = T.search(word);

				if (!TN)
				{
					TN = T.insert(word);
				}
				else
				{
					TN->frequency++;
				}
				mh.insert(TN, word);
				
			}
			mh.Display();
		}
		in.close();
	}
}

Last edited on

lastchance (6980)

"Your" code?

You mean this one?
https://codereview.stackexchange.com/questions/241192/finding-the-k-most-frequent-words-in-file-in-c

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collection not returning anything