Added files

Author: avidLearnerInProgress

amazon/minimum_distance_between_nodes.cpp

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+#include <iostream> 
+using namespace std; 
+  
+// A Binary Tree Node 
+struct Node 
+{ 
+    struct Node *left, *right; 
+    int key; 
+}; 
+  
+// Utility function to create a new tree Node 
+Node* newNode(int key) 
+{ 
+    Node *temp = new Node; 
+    temp->key = key; 
+    temp->left = temp->right = NULL; 
+    return temp; 
+} 
+Node* LCA(Node * root, int n1,int n2) 
+{ 
+    // Your code here 
+    if (root == NULL) 
+       return root; 
+    if (root->key == n1 || root->key == n2) 
+       return root; 
+  
+    Node* left = LCA(root->left, n1, n2); 
+    Node* right = LCA(root->right, n1, n2); 
+  
+    if (left != NULL && right != NULL) 
+         return root; 
+    if (left != NULL) 
+        return LCA(root->left, n1, n2); 
+  
+    return LCA(root->right, n1, n2); 
+} 
+  
+// Returns level of key k if it is present in 
+// tree, otherwise returns -1 
+void search(struct Node* root,int a,int level,int &get_level)
+{
+    if(root==NULL)
+    {
+        return;
+    }
+    if(root->key==a)
+    {
+        get_level = level;
+    }
+    search(root->left,a,level+1,get_level);
+    search(root->right,a,level+1,get_level);
+}
+  
+int findDistance(Node* root, int a, int b) 
+{ 
+    // Your code here 
+    int level = 0;
+    int x,y=0;
+    Node* lca = LCA(root, a , b); 
+    search(lca,a,0,x);
+    search(lca,b,0,y);
+    return x + y;
+} 
+  
+// Driver program to test above functions 
+int main() 
+{ 
+    // Let us create binary tree given in 
+    // the above example 
+    Node * root = newNode(1); 
+    root->left = newNode(2); 
+    root->right = newNode(3); 
+    root->left->left = newNode(4); 
+    root->left->right = newNode(5); 
+    root->right->left = newNode(6); 
+    root->right->right = newNode(7); 
+    root->right->left->right = newNode(8); 
+    cout << "Dist(4, 5) = " << findDistance(root, 4, 5); 
+    cout << "\nDist(4, 6) = " << findDistance(root, 4, 6); 
+    cout << "\nDist(3, 4) = " << findDistance(root, 3, 4); 
+    cout << "\nDist(2, 4) = " << findDistance(root, 2, 4); 
+    cout << "\nDist(8, 5) = " << findDistance(root, 8, 5); 
+    return 0; 
+}