Merge pull request #768 from ABHIT33/main

K distance from root.cpp

Author: spandey1296

binary-tree/K distance from root.cpp

@@ -0,0 +1,141 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+struct Node
+{
+    int data;
+    struct Node *left;
+    struct 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;
+}
+
+vector<int> Kdistance(struct Node *root, int k);
+
+int main()
+{
+
+    int t;
+	scanf("%d ",&t);
+    while(t--)
+    {
+        int k;
+		scanf("%d ",&k);
+        string s;
+		getline(cin,s);
+        Node* root = buildTree(s);
+        vector<int> vec = Kdistance(root, k);
+        for(int i = 0;i<vec.size();i++){
+            cout<<vec[i]<<" ";
+        }
+        cout<<endl;
+    }
+    return 1;
+}// } Driver Code Ends
+
+
+/* A binary tree node has data, pointer to left child
+   and a pointer to right child /
+struct Node
+{
+    int data;
+    Node* left;
+    Node* right;
+}; */
+
+// function should print the nodes at k distance from root
+void kdistance(struct Node *root, int k,vector<int> &v)
+{
+    if(root==NULL)
+        return;
+
+    if(k==0)
+    {
+        v.push_back(root->data);
+        return;
+    }
+        
+    else
+    {
+        kdistance(root->left,k-1,v);
+        kdistance(root->right,k-1,v);
+    }
+}
+vector<int> Kdistance(struct Node *root, int k)
+{
+  // Your code here
+  vector<int>v;
+  kdistance(root,k,v);
+  return v;
+}