Create 971-flip-binary-tree-to-match-preorder-traversal.js

Author: everthis

971-flip-binary-tree-to-match-preorder-traversal.js

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+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @param {number[]} voyage
+ * @return {number[]}
+ */
+const flipMatchVoyage = function (root, voyage) {
+  const n = voyage.length
+  const res = []
+  let idx = 0
+  return dfs(root, 0) ? res : [-1]
+
+  function dfs(node) {
+    if (node == null) return true
+    if (node.val !== voyage[idx]) {
+      return false
+    }
+    idx++
+    if (node.left && node.left.val !== voyage[idx]) {
+      res.push(node.val)
+      return dfs(node.right) && dfs(node.left)
+    }
+    return dfs(node.left) && dfs(node.right)
+  }
+}