Leetcode during internship

Author: Gael Estrera

Leetcode/SymmetricTree.java

@@ -0,0 +1,39 @@
+/**
+ * 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 IsMeasure(TreeNode left, TreeNode right){
+        if (left == null && right == null){
+            return true;
+        }
+        if (left == null && right != null){
+            return false;
+        }
+        if (right == null && left != null){
+            return false;
+        }
+        
+        return left.val == right.val && IsMeasure(left.left, right.right) && IsMeasure(left.right, right.left);
+    }
+
+    public boolean isSymmetric(TreeNode root) {
+        
+        if (root == null){
+            return true;
+        }
+
+        return IsMeasure(root.left, root.right);
+    }
+}

Leetcode/TreeDepth.java

@@ -0,0 +1,34 @@
+/**
+ * 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 counter = 0;
+    public int depth(TreeNode node){
+        if (node == null){
+            return 0;
+        }
+        int leftdepth = depth(node.left);
+        int rightdepth = depth(node.right);
+
+        if (leftdepth > rightdepth){return leftdepth + 1;}
+        else {return rightdepth + 1;}
+
+    }
+
+    public int maxDepth(TreeNode root) {
+        if (root == null) return 0;
+        return depth(root);
+    }
+}

Leetcode/minDepth.java

@@ -0,0 +1,31 @@
+/**
+ * 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;
+        int leftdepth = minDepth(root.left);
+        int rightdepth = minDepth(root.right);
+        if (leftdepth < rightdepth && leftdepth != 0){
+            return leftdepth + 1;
+        } else if (rightdepth < leftdepth && rightdepth != 0){
+            return rightdepth + 1;
+        } else if (rightdepth < leftdepth && rightdepth == 0){
+            return leftdepth + 1;
+        }
+        //if left depth < rightdepth and left depth == 0
+        return rightdepth + 1;
+    }
+}