Create main.cpp

Author: JawadSher

17 - Binary Tree Data Structure Problems/28 - Kth Ancestor in a Tree/main.cpp

@@ -0,0 +1,38 @@
+Node* solve(Node* root, int& k, int node){
+    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);
+    
+    if(leftAns != NULL && rightAns == NULL){
+        k--;
+        if(k <= 0) {
+            k = INT_MAX;
+            return root;
+        }
+        
+        return leftAns;
+    }
+    
+    if(leftAns == NULL && rightAns != NULL){
+        k--;
+        if(k <= 0) {
+            k = INT_MAX;
+            return root;
+        }
+        
+        return rightAns;
+    }
+    
+    return NULL;
+}
+
+int kthAncestor(Node *root, int k, int node)
+{
+    Node* ancestor = solve(root, k, node);
+    if(ancestor == NULL || ancestor -> data == node) return -1;
+    
+    return ancestor->data;
+}