Time: 4 ms (77.33%) | Memory: 63.3 MB (39.21%) - LeetSync

111-minimum-depth-of-binary-tree/minimum-depth-of-binary-tree.java

@@ -0,0 +1,29 @@
+/**
+ * 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 int minDepth(TreeNode root) {
+        if (root == null) {
+            return 0;
+        }
+        if (root.left == null) {
+            return 1 + minDepth(root.right);
+        }
+        if (root.right == null) {
+            return minDepth(root.left) + 1;
+        }
+        return Math.min(minDepth(root.left), minDepth(root.right)) + 1;
+    }
+}