Added 1 solution & modified 1 solution

varunu28 · varunu28 · commit 8c852c307e89 · 2020-02-11T21:07:33.000-08:00
diff --git a/Easy/Increasing Order Search Tree.java b/Easy/Increasing Order Search Tree.java
@@ -8,32 +8,22 @@
  * }
  */
 class Solution {
-    
-    public List<TreeNode> list = new ArrayList<>();
-    public TreeNode increasingBST(TreeNode root) {
-        inorderTraversal(root);
-        
-        if (list.size() == 0) return null;
-        
-        TreeNode ans = list.get(0);
-        TreeNode curr = ans;
-        
-        for (int i=1; i<list.size(); i++) {
-            curr.right = list.get(i);
-            curr.left = null;
-            curr = curr.right;
-        }
-        
-        curr.left = null;
-        
-        return ans;
-    }
-    
-    public void inorderTraversal(TreeNode root) {
-        if (root == null) return;
-        
-        inorderTraversal(root.left);
-        list.add(root);
-        inorderTraversal(root.right);
+  TreeNode curr;
+  public TreeNode increasingBST(TreeNode root) {
+    TreeNode ans = new TreeNode(-1);
+    curr = ans;
+    inorder(root);
+    return ans.right;
+  }
+  
+  private void inorder(TreeNode node) {
+    if (node == null) {
+      return;
     }
+    inorder(node.left);
+    node.left = null;
+    curr.right = node;
+    curr = node;
+    inorder(node.right);
+  }
 }
diff --git a/Easy/Leaf Similar Tree.java b/Easy/Leaf Similar Tree.java
@@ -0,0 +1,31 @@
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode(int x) { val = x; }
+ * }
+ */
+class Solution {
+  public boolean leafSimilar(TreeNode root1, TreeNode root2) {
+    List<Integer> leaf1 = new ArrayList<>();
+    List<Integer> leaf2 = new ArrayList<>();
+    populateLeaves(root1, leaf1);
+    populateLeaves(root2, leaf2);
+    return leaf1.equals(leaf2);
+  }
+  
+  private void populateLeaves(TreeNode root, List<Integer> list) {
+    if (root == null) {
+      return;
+    }
+    if (root.left == null && root.right == null) {
+      list.add(root.val);
+    }
+    else {
+      populateLeaves(root.left, list);
+      populateLeaves(root.right, list);
+    }
+  }
+}
