CareerCup

get the words from paragraph by searching for blank spaces and store the words in vector or binary tree.
If you use vector then run a loop through the vector search for same words.

If use binary tree for storing words, you can arrange words around the root..example

"RAM is a boy. Ram is a Great boy"

make ROOT= "RAM"

and arrange words in binary tree like this
if(root->data>newData)
{
//insert at left
}
else if(root->data<newData)
{
//insert at right
}
else if(root->data==data)
{
//same word found, store this in some global vector
}


Hence using Binary tree will save you resource of looping for every word in vector used for storing data.

code for creating tree modify this for storing paragraph and add check for EQUALS while creating tree.

#include<iostream>
#include<string>

using namespace std;


//tree node
struct TreeNode{
	string data;
	TreeNode *leftNode;
	TreeNode *rightNode;
	TreeNode(){}
	TreeNode(string data){this->data=data;}
};


//binary tree
class BinaryTree{

	TreeNode* rootNode;
	//create binary tree
	void createTree(TreeNode*& rootNode,string data);
	void showTree(TreeNode*& root);

public:
	BinaryTree(){rootNode=NULL;}

	//starting point for creating tree, root is accessed from this func
	void insert(string data)
	{
		createTree(rootNode,data);
	}
	//show tree
	void BinaryTree::show()
	{
		showTree(rootNode);
	}

};

void BinaryTree::createTree(TreeNode*& root,string data)
{
	//check if root is NULL, this is called recursively for left or right side,for every new node
	if(root==NULL)
	{
		root=new TreeNode(data);
		root->leftNode=NULL;
		root->rightNode=NULL;
		return;
	}
	if(root->data[0]<data[0])
	{
		createTree(root->leftNode,data);
	}
	else
	{
		createTree(root->rightNode,data);
	}

}

void BinaryTree::showTree(TreeNode*& root)
{
	//check if root is NULL, this is called recursively for left or right side,for every new node
	if(root==NULL)
	{
		return;
	}
	showTree(root->leftNode);
	cout<<root->data<<endl;
	showTree(root->rightNode);
}




int main()
{
	BinaryTree tree;
	tree.insert("cd");
	tree.insert("6");
	tree.insert("asd");
	tree.insert("1");
	tree.insert("B");
	tree.insert("4");
	tree.insert("5");
	tree.insert("avs");
	tree.insert("A");
	tree.show();

	getchar();
	return 0;
}

How abt tries?

create a trie of the text then just use the hash table for storing the count of words.

What about hashing ?
Before insertion check whether it is present before Inserting if no insert it with value 1 and if yes then increment the value with 1.