Create: 0095-unique-binary-search-trees-ii.java

Signed-off-by: Aliaksei <[email protected]>

Author: a1exanddrovich

java/0095-unique-binary-search-trees-ii.java

@@ -0,0 +1,27 @@
+class Solution {
+    public List<TreeNode> generateTrees(int n) {
+        return generate(1, n);
+    }
+
+    private List<TreeNode> generate(int left, int right) {
+        if (left > right) {
+            List<TreeNode> r = new ArrayList<>();
+            r.add(null);
+            return r;
+        }
+
+        List<TreeNode> res = new ArrayList<>();
+        for (int val = left; val <= right; val++) {
+            for (TreeNode leftSubtree : generate(left, val - 1)) {
+                for (TreeNode rightSubtree: generate(val + 1, right)) {
+                    TreeNode root = new TreeNode(val);
+                    root.left = leftSubtree;
+                    root.right = rightSubtree;
+                    res.add(root);
+                }
+            }
+        }
+
+        return res;
+    }
+}