If I was asked about number of nodes in binary tree, it would be so easy but I am asked to count number of distinct nodes in binary tree like below. There are two 12 values!
Number of nodes in binary tree algoritm is this:
struct Node {
string data;
struct Node *left;
struct Node *right;
};
int getNumberOfNodes(Node* node)
{
if (node != NULL)
return getNumberOfNodes(node->left) + 1 + getNumberOfNodes(node->right);
else
return 0;
}
But for unique values, it is too hard -_-
You can change your function adding a container to maintain the values you already encountered. The best container has been suggested in the comment std::set
.
The new code would be:
int getNumberOfNodes(Node* node, std::set<string>& uniqueValues)
{
if (node != NULL)
{
int count = 0;
if ( uniqueValues.find( node->data ) == uniqueValues.end() )
{
count = 1;
uniqueValues.insert ( node->data );
}
return getNumberOfNodes(node->left,uniqueValues) + count + getNumberOfNodes(node->right,uniqueValues);
}
else
return 0;
}
Not so different from your code.
At the end the uniqueValues.size()
will be equal to the returned int.
Clear the uniqueValues
before calling the function.
int count_label(Node *root, int data)
{
int count_of_data = 0;
if(root == NULL)
return 0;
if(data == root->data)
count_of_data += 1;
if(data > root->data)
count_of_data += count_label(root->right,data);
else
count_of_data += count_label(root->left,data);
return count_of_data;
}
//--------------------------------------------------------
unsigned int unique_nodes(Node *root)
{
int count_u = 0;
if(root == NULL)
return 0;
if(count_label(root, root->data) == 1)
{
count_u += 1;
}
count_u += unique_nodes(root->left);
count_u += unique_nodes(root->right);
return count_u;
}
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