Create 662-maximum-width-of-binary-tree.js

Author: everthis

662-maximum-width-of-binary-tree.js

@@ -0,0 +1,31 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+const widthOfBinaryTree = function(root) {
+    const mins = [0]
+    let max = 0
+  
+    dfs(root, 0, 0)
+    return max
+  
+    // depth first search
+    function dfs(currentNode, depth, position) {
+      if (!currentNode) return
+      if (depth === mins.length) {
+        mins[depth] = position
+      }
+  
+      const delta = position - mins[depth]
+      max = Math.max(max, delta + 1)
+      dfs(currentNode.left, depth + 1, delta * 2)
+      dfs(currentNode.right, depth + 1, delta * 2 + 1)
+    }
+  }