diff --git a/371-Sum-of-Two-Integers.java b/371-Sum-of-Two-Integers.java
index ff641469f..9e92f51b3 100644
--- a/371-Sum-of-Two-Integers.java
+++ b/371-Sum-of-Two-Integers.java
@@ -7,4 +7,4 @@ public int getSum(int a, int b) {
         }
         return a;
     }
-}
+}
\ No newline at end of file
diff --git a/java/100-Same-Tree.java b/java/100-Same-Tree.java
new file mode 100644
index 000000000..851486e05
--- /dev/null
+++ b/java/100-Same-Tree.java
@@ -0,0 +1,40 @@
+package java;
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode() {}
+ *     TreeNode(int val) { this.val = val; }
+ *     TreeNode(int val, TreeNode left, TreeNode right) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+class Solution {
+    public boolean isSameTree(TreeNode p, TreeNode q) {
+        return dfs(p, q);
+    }
+    
+    private boolean dfs(TreeNode p, TreeNode q) {
+        if (p == null && q == null) {
+            return true;
+        }
+        
+        if (p == null || q == null) {
+            return false;
+        }
+        
+        if (p.val != q.val) return false;
+        
+        boolean left = dfs(p.left, q.left);
+        boolean right = dfs(p.right, q.right);
+        
+        return left && right;
+    }
+}
+
diff --git a/java/124-Binary-Tree-Maximum-Path-Sum.java b/java/124-Binary-Tree-Maximum-Path-Sum.java
new file mode 100644
index 000000000..22d94a98f
--- /dev/null
+++ b/java/124-Binary-Tree-Maximum-Path-Sum.java
@@ -0,0 +1,43 @@
+package java;
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ *     int val;
+ *     TreeNode left;
+ *     TreeNode right;
+ *     TreeNode() {}
+ *     TreeNode(int val) { this.val = val; }
+ *     TreeNode(int val, TreeNode left, TreeNode right) {
+ *         this.val = val;
+ *         this.left = left;
+ *         this.right = right;
+ *     }
+ * }
+ */
+class Solution {
+    
+    int[] res = new int[1];
+    
+    public int maxPathSum(TreeNode root) {
+        res[0] = root.val;
+        dfs(root);
+        return res[0];
+    }
+    
+    private int dfs(TreeNode node) {
+        if (node == null) return 0;
+        
+        int leftMax = dfs(node.left);
+        int rightMax = dfs(node.right);
+        
+        leftMax = Math.max(leftMax, 0);
+        rightMax = Math.max(rightMax, 0);
+        
+        int allMax = leftMax + rightMax + node.val;
+        res[0] = Math.max(res[0], allMax);
+        
+        
+        return node.val + Math.max(leftMax, rightMax);
+    }
+}
\ No newline at end of file
diff --git a/java/21-Merge-Two-Sorted-Lists.java b/java/21-Merge-Two-Sorted-Lists.java
index 3dc9aadbe..a8d94b564 100644
--- a/java/21-Merge-Two-Sorted-Lists.java
+++ b/java/21-Merge-Two-Sorted-Lists.java
@@ -1,3 +1,5 @@
+package java;
+
 /**
  * Definition for singly-linked list.
  * public class ListNode {