New algo for tree added

algorithms/CPlusPlus/Trees/All-Nodes-Distance-K-in-Binary-Tree.cpp

@@ -0,0 +1,109 @@
+/*
+Problem: Return an array of the values of all nodes that have
+a distance k from the target node.
+*/
+
+/*-------------------------
+Recursive Solution
+Time Complexity: O(n)
+---------------------*/
+
+#include <iostream>
+#include <vector>
+using namespace std;
+
+// Basic Structure of a tree
+class Node
+{
+private:
+    int data;
+    Node *left;
+    Node *right;
+
+public:
+    Node(int value)
+    {
+        data = value;
+        left = NULL;
+        right = NULL;
+    }
+
+    void insert(Node *&root, int data)
+    {
+
+        if (root == NULL)
+            root = new Node(data);
+        else if (root->data > data)
+            insert(root->left, data);
+        else
+            insert(root->right, data);
+    }
+    vector<int> v;
+    void kdown(Node *root, Node *block, int k)
+    {
+        if (root == NULL or root == block or k < 0)
+        {
+            return;
+        }
+        if (k == 0)
+        {
+            v.push_back(root->data);
+            return;
+        }
+        kdown(root->left, block, k - 1);
+        kdown(root->right, block, k - 1);
+    }
+    int k_help(Node *root, Node *target, int k)
+    {
+        if (root == NULL)
+            return -1;
+        if (root == target)
+        {
+            kdown(root, NULL, k);
+            return 1;
+        }
+        int ld = k_help(root->left, target, k);
+        if (ld != -1)
+        {
+            kdown(root, root->left, k - ld);
+            return 1 + ld;
+        }
+        int rd = k_help(root->right, target, k);
+        if (rd != -1)
+        {
+            kdown(root, root->right, k - rd);
+            return 1 + rd;
+        }
+        return -1;
+    }
+    vector<int> distanceK(Node *root, Node *target, int k)
+    {
+        k_help(root, target, k);
+        return v;
+    }
+};
+
+int main()
+{
+    // User Input
+    Node *root = NULL;
+    Node *tar;
+    int n, num, tar, k;
+    cout << "Enter the Number of nodes :";
+    cin >> n;
+    cout << "\nEnter the value of the nodes :";
+    for (int i = 0; i < n; i++)
+    {
+        cin >> num;
+        root->insert(root, num);
+    }
+    cout << "\nEnter the target value :" << tar;
+    cout << "Enter the distance you to search :" << k;
+    vector<int> v = root->distanceK(root, tar, k);
+    for (auto i : v)
+    {
+        cout << i << " ";
+    }
+
+    return 0;
+}