DIY: Validate the Binary Search Tree

Solve the interview question "Validate the Binary Search Tree" in this lesson.

Problem statement

For this challenge, you are given an integer array. You have to implement the InorderBST() function to validate whether the given integer array represents the in-order traversal of a valid binary search tree.


  • Nodes count of the binary search tree in the range [1, 10410^4].
  • 231-2^{31} <= Node.value <= 2312^{31} - 1


The input of the InorderBST() function is an integer array and its length. The following is an example input:



The following is the output of the InorderBST() function, in case it fulfills the condition:


Otherwise, it outputs the following:


Coding exercise

Implement the InorderBST(array,n) function, where array is an integer array that represents the in-order traversal of a binary search tree, and n is the given array’s length.

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