Create 199-binary-tree-right-side-view.js

Author: everthis

199-binary-tree-right-side-view.js

@@ -0,0 +1,26 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number[]}
+ */
+const rightSideView = function(root) {
+  if(root == null) return []
+  const queue = [root]
+  const res = []
+  while(queue.length) {
+    const len = queue.length
+    for(let i = 0; i < len; i++) {
+      const el = queue.shift()
+      if(i === len - 1) res.push(el.val)
+      if(el.left) queue.push(el.left)
+      if(el.right) queue.push(el.right)
+    }
+  }
+  return res
+};