Create 117-populating-next-right-pointers-in-each-node-ii.js

Author: everthis

117-populating-next-right-pointers-in-each-node-ii.js

@@ -0,0 +1,28 @@
+/**
+ * // Definition for a Node.
+ * function Node(val,left,right,next) {
+ *    this.val = val;
+ *    this.left = left;
+ *    this.right = right;
+ *    this.next = next;
+ * };
+ */
+/**
+ * @param {Node} root
+ * @return {Node}
+ */
+const connect = function(root) {
+  if (root == null) return null
+  const cur = [root]
+  while (cur.length) {
+    const len = cur.length
+    for (let i = 0; i < len; i++) {
+      const el = cur.shift()
+      if (i === len - 1) el.next = null
+      else el.next = cur[0]
+      if (el.left) cur.push(el.left)
+      if (el.right) cur.push(el.right)
+    }
+  }
+  return root
+}