Create All possible full binary tree.cpp

Author: sanyathisside

Diff for: LeetCode/All possible full binary tree.cpp

@@ -0,0 +1,23 @@
+class Solution {
+public:
+    vector<TreeNode*> allPossibleFBT(int n) {
+	
+        if(n&1 == 0)return {}; //FBT can have only odd number of nodes
+        if(n == 1)return {new TreeNode()};
+		
+        vector<TreeNode*>res;
+		
+        for(int i = 1; i < n-1;i+=2){  //incrementation by 2 to avoid redundant recursive call for even number of nodes
+		
+            vector<TreeNode*>left = allPossibleFBT(i);
+            vector<TreeNode*>right = allPossibleFBT(n-i-1);  //1 is reserved for root node, hence n-i-1
+			
+            for(auto l : left)
+                for(auto r : right)
+                    TreeNode* root = new TreeNode(), root->left = l, root->right = r, res.push_back(root);
+        }
+		
+        return res;
+        
+    } 
+};