Given two integer arrays preorder
and inorder
representing traversals of a binary tree:
preorder
contains the preorder traversal (root, left, right)inorder
contains the inorder traversal (left, root, right)Both arrays:
Construct and return the original binary tree.
Constraints:
Examples:
// Example 1:
// 1
// / \
// 2 3
// \
// 4
const preorder1 = [1, 2, 3, 4];
const inorder1 = [2, 1, 3, 4];
console.log(buildTree(preorder1, inorder1));
// Output: [1, 2, 3, null, null, null, 4]
// Example 2:
// 1
const preorder2 = [1];
const inorder2 = [1];
console.log(buildTree(preorder2, inorder2));
// Output: [1]