Adding codes for Lecture 65

Lecture065 Tree Interview Questions Day3/bloodline.cpp

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+// { Driver Code Starts
+//Initial Template for C++
+
+#include <bits/stdc++.h>
+using namespace std;
+
+struct Node
+{
+    int data;
+    struct Node *left;
+    struct Node *right;
+
+    Node(int x)
+    {
+        data = x;
+        left = NULL;
+        right = NULL;
+    }
+};
+
+void printInorder(Node *node)
+{
+    if (node == NULL)
+    {
+        return;
+    }
+    printInorder(node->left);
+    cout << node->data << " ";
+    printInorder(node->right);
+}
+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 = new Node(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 = new Node(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 = new Node(stoi(currVal));
+
+            // Push it to the queue
+            queue.push(currNode->right);
+        }
+        i++;
+    }
+
+    return root;
+}
+
+
+ // } Driver Code Ends
+//User function Template for C++
+
+/*
+structure of the node of the binary tree is as
+struct Node
+{
+    int data;
+    struct Node *left;
+    struct Node *right;
+
+    Node(int x)
+    {
+        data = x;
+        left = NULL;
+        right = NULL;
+    }
+};
+*/
+class Solution
+{
+public:
+
+    void solve(Node* root, int sum, int &maxSum, int len, int &maxLen) {
+        //base case
+        if( root == NULL ) {
+
+            if(len > maxLen) 
+            {
+                maxLen = len;
+                maxSum = sum;
+            }
+            else if(len == maxLen) 
+            {
+                maxSum = max(sum, maxSum);
+            }
+            return;
+        }
+
+        sum = sum + root->data;
+
+        solve(root->left, sum, maxSum, len+1, maxLen);
+        solve(root->right, sum, maxSum, len+1, maxLen);
+
+    }
+
+    int sumOfLongRootToLeafPath(Node *root)
+    {
+        int len = 0;
+        int maxLen = 0;
+
+        int sum = 0;
+        int maxSum = INT_MIN;
+
+        solve(root, sum, maxSum, len, maxLen);
+
+        return maxSum;
+    }
+};
+
+// { Driver Code Starts.
+
+int main()
+{
+
+    int t;
+    scanf("%d", &t);
+    cin.ignore();
+    while (t--)
+    {
+        string treeString;
+        getline(cin, treeString);
+        Node *root = buildTree(treeString);
+        Solution obj;
+        int res = obj.sumOfLongRootToLeafPath(root);
+        cout << res << "\n";
+    }
+    return 0;
+}  // } Driver Code Ends

Lecture065 Tree Interview Questions Day3/kAncestor.cpp

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+// { Driver Code Starts
+#include <bits/stdc++.h>
+using namespace std;
+
+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;
+}
+int kthAncestor(Node *root, int k, int node);
+
+int main()
+{
+    int t;
+	scanf("%d ",&t);
+    while(t--)
+    {
+        int k , node;
+        scanf("%d ",&k);
+        scanf("%d ",&node);
+        string s;
+		getline(cin,s);
+		Node* root = buildTree(s);
+		cout<<kthAncestor(root,k,node)<<endl;
+    }
+    return 0;
+}
+// } Driver Code Ends
+
+
+//User function Template for C++
+/*
+Structure of the node of the binary tree is as
+struct Node
+{
+	int data;
+	struct Node *left, *right;
+};
+*/
+// your task is to complete this function
+Node* solve(Node* root, int &k, int node) {
+    //base case
+    if(root == NULL)
+        return NULL;
+
+    if(root->data == node) 
+    {
+        return root;
+    }
+
+    Node* leftAns = solve(root->left, k, node);
+    Node* rightAns = solve(root->right, k, node);
+
+
+    //wapas
+    if(leftAns != NULL && rightAns == NULL) 
+    {
+        k--;
+        if(k<=0) 
+        {
+            //answer lock
+            k = INT_MAX;
+            return root;
+        }
+        return leftAns;
+    }
+
+    if(leftAns == NULL && rightAns != NULL) {
+        k--;
+        if(k<=0) 
+        {
+            //answer lock
+            k = INT_MAX;
+            return root;
+        }
+        return rightAns;
+    }
+    return NULL;
+
+
+}
+int kthAncestor(Node *root, int k, int node)
+{
+    Node* ans = solve(root, k, node);
+    if(ans == NULL || ans->data == node)
+        return -1;
+    else
+        return ans->data;
+}