Added solutions

Author: avidLearnerInProgress

amazon/count_bstnodes_within_range.cpp

@@ -0,0 +1,87 @@
+{
+#include <bits/stdc++.h>
+using namespace std;
+struct Node {
+    int data;
+    Node* right;
+    Node* left;
+    
+    Node(int x){
+        data = x;
+        right = NULL;
+        left = NULL;
+    }
+};
+Node *insert(Node *root,int data)
+{
+    if(root==NULL)
+    root=new Node(data);
+    else if(data<root->data)
+    root->left=insert(root->left,data);
+    else
+    root->right=insert(root->right,data);
+    
+    return root;
+}
+//Position this line where user code will be pasted.
+int main() {
+    
+    int testcases;
+    cin>>testcases;
+    while(testcases--)
+    {
+        Node *root=NULL;
+        int sizeOfArray;
+        cin>>sizeOfArray;
+        int arr[sizeOfArray];
+        
+        for(int i=0;i<sizeOfArray;i++)
+        cin>>arr[i];
+        
+        for(int i=0;i<sizeOfArray;i++)
+        {
+            root=insert(root,arr[i]);
+        }
+        int l,h;
+        cin>>l>>h;
+        cout<<getCountOfNode(root,l,h)<<endl;
+    
+        
+    }
+	return 0;
+}
+}
+/*This is a function problem.You only need to complete the function given below*/
+/*
+The structure of a BST node is as follows:
+struct Node {
+    int data;
+    Node* right;
+    Node* left;
+    
+    Node(int x){
+        data = x;
+        right = NULL;
+        left = NULL;
+    }
+};
+*/
+int getCountOfNode(Node *root, int l, int h)
+{
+    // your code goes here   
+    if(!root) return 0;
+    queue<Node*> q;
+    int count = 0;
+    q.push(root);
+    while(!q.empty()){
+        Node *front = q.front();
+        q.pop();
+        if(front->data >= l && front->data <= h)
+            count++;
+        if(front->left)
+            q.push(front->left);
+        if(front->right)
+            q.push(front->right);
+    }
+    return count;
+}