Adding codes for Lecture 63

Lecture063 Tree Interview Questions Day1/balancedTree.cpp

@@ -0,0 +1,164 @@
+//Initial Template for C++
+
+
+#include <bits/stdc++.h>
+using namespace std;
+
+
+// Tree Node
+struct Node {
+    int data;
+    Node* left;
+    Node* right;
+};
+
+// Utility function to create a new Tree Node
+Node* newNode(int val) {
+    Node* temp = new Node;
+    temp->data = val;
+    temp->left = NULL;
+    temp->right = NULL;
+
+    return temp;
+}
+
+
+// Function to Build Tree
+Node* buildTree(string str) {
+    // Corner Case
+    if (str.length() == 0 || str[0] == 'N') return NULL;
+
+    // Creating vector of strings from input
+    // string after spliting by space
+    vector<string> ip;
+
+    istringstream iss(str);
+    for (string str; iss >> str;) ip.push_back(str);
+
+    // Create the root of the tree
+    Node* root = newNode(stoi(ip[0]));
+
+    // Push the root to the queue
+    queue<Node*> queue;
+    queue.push(root);
+
+    // Starting from the second element
+    int i = 1;
+    while (!queue.empty() && i < ip.size()) {
+
+        // Get and remove the front of the queue
+        Node* currNode = queue.front();
+        queue.pop();
+
+        // Get the current node's value from the string
+        string currVal = ip[i];
+
+        // If the left child is not null
+        if (currVal != "N") {
+
+            // Create the left child for the current node
+            currNode->left = newNode(stoi(currVal));
+
+            // Push it to the queue
+            queue.push(currNode->left);
+        }
+
+        // For the right child
+        i++;
+        if (i >= ip.size()) break;
+        currVal = ip[i];
+
+        // If the right child is not null
+        if (currVal != "N") {
+
+            // Create the right child for the current node
+            currNode->right = newNode(stoi(currVal));
+
+            // Push it to the queue
+            queue.push(currNode->right);
+        }
+        i++;
+    }
+
+    return root;
+}
+
+
+ // } Driver Code Ends
+/* A binary tree node structure
+
+struct Node
+{
+    int data;
+    struct Node* left;
+    struct Node* right;
+    
+    Node(int x){
+        data = x;
+        left = right = NULL;
+    }
+};
+ */
+
+class Solution{
+    public:
+    //Function to check whether a binary tree is balanced or not.
+    pair<bool, int> isBalancedFast(Node* root) {
+                // base case
+        if(root == NULL)
+        {
+            pair<bool, int> p = make_pair(true, 0);
+            return p;
+        }
+
+        pair<int,int> left = isBalancedFast(root->left);
+        pair<int,int> right = isBalancedFast(root->right);
+
+
+        bool leftAns = left.first;
+        bool rightAns = right.first;
+
+        bool diff = abs (left.second - right.second ) <=1;
+
+        pair<bool,int> ans;
+        ans.second = max(left.second, right.second) + 1;
+
+        if(leftAns && rightAns && diff) {
+           ans.first = true;
+        }
+        else
+        {
+            ans.first = false;
+        }
+        return ans;
+    }
+    bool isBalanced(Node *root)
+    {
+        return isBalancedFast(root).first;
+    }
+
+};
+
+
+// { Driver Code Starts.
+
+/* Driver program to test size function*/
+
+
+
+int main() {
+
+
+    int t;
+    scanf("%d ", &t);
+    while (t--) {
+        string s, ch;
+        getline(cin, s);
+
+        Node* root = buildTree(s);
+        Solution ob;
+        cout << ob.isBalanced(root) << endl;
+    }
+    return 0;
+}
+  // } Driver Code Ends

Lecture063 Tree Interview Questions Day1/diameter.cpp

@@ -0,0 +1,152 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+/* A binary tree node has data, pointer to left child
+   and a pointer to right child */
+struct Node {
+    int data;
+    struct Node* left;
+    struct Node* right;
+};
+Node* newNode(int val) {
+    Node* temp = new Node;
+    temp->data = val;
+    temp->left = NULL;
+    temp->right = NULL;
+    return temp;
+}
+Node* buildTree(string str) {
+    // Corner Case
+    if (str.length() == 0 || str[0] == 'N') return NULL;
+
+    // Creating vector of strings from input
+    // string after spliting by space
+    vector<string> ip;
+
+    istringstream iss(str);
+    for (string str; iss >> str;) ip.push_back(str);
+
+    // Create the root of the tree
+    Node* root = newNode(stoi(ip[0]));
+
+    // Push the root to the queue
+    queue<Node*> queue;
+    queue.push(root);
+
+    // Starting from the second element
+    int i = 1;
+    while (!queue.empty() && i < ip.size()) {
+
+        // Get and remove the front of the queue
+        Node* currNode = queue.front();
+        queue.pop();
+
+        // Get the current node's value from the string
+        string currVal = ip[i];
+
+        // If the left child is not null
+        if (currVal != "N") {
+
+            // Create the left child for the current node
+            currNode->left = newNode(stoi(currVal));
+
+            // Push it to the queue
+            queue.push(currNode->left);
+        }
+
+        // For the right child
+        i++;
+        if (i >= ip.size()) break;
+        currVal = ip[i];
+
+        // If the right child is not null
+        if (currVal != "N") {
+
+            // Create the right child for the current node
+            currNode->right = newNode(stoi(currVal));
+
+            // Push it to the queue
+            queue.push(currNode->right);
+        }
+        i++;
+    }
+
+    return root;
+}
+
+
+ // } Driver Code Ends
+/* Tree node structure  used in the program
+
+struct Node
+{
+    int data;
+    struct Node* left;
+    struct Node* right;
+
+    Node(int x){
+        data = x;
+        left = right = NULL;
+    }
+}; */
+
+class Solution {
+  private:
+    int height(struct Node* node){
+        //base case
+        if(node == NULL) {
+            return 0;
+        }
+
+        int left = height(node ->left);
+        int right = height(node->right);
+
+        int ans = max(left, right) + 1;
+        return ans;
+    }
+  public:
+    // Function to return the diameter of a Binary Tree.
+
+    pair<int,int> diameterFast(Node* root) {
+        //base case
+        if(root == NULL) {
+            pair<int,int> p = make_pair(0,0);
+            return p;
+        }
+
+        pair<int,int> left = diameterFast(root->left);
+        pair<int,int> right = diameterFast(root->right);
+
+        int op1 = left.first;
+        int op2 = right.first;
+        int op3 = left.second + right.second + 1;
+
+        pair<int,int> ans;
+        ans.first = max(op1, max(op2, op3));;
+        ans.second = max(left.second , right.second) + 1;
+
+        return ans;
+    }
+    int diameter(Node* root) {
+
+        return diameterFast(root).first;
+
+    }
+};
+
+// { Driver Code Starts.
+
+/* Driver program to test size function*/
+int main() {
+    int t;
+    scanf("%d\n", &t);
+    while (t--) {
+        string s;
+        getline(cin, s);
+        Node* root = buildTree(s);
+        Solution ob;
+        cout << ob.diameter(root) << endl;
+    }
+    return 0;
+}
+  // } Driver Code Ends