Meta Intern interview questions

On campus interview: 1) How would you implement a Naive String matching program? 2) How do you know when if a binary tree is a BST? On site interview: 1) Given 2 strings that you are reading from 2 streams (so you don't know the length of any of the strings and the only method you have is getNextChar() for each string), implement a program that tells you when 2 of these strings are 1 edit away from being the same. 1- edit is defined as a single insert char, single remove char or single modify/change char in only 1 of the strings.

Given an integer x and an array y, create a function that returns true if x exists as a sum of any contiguous elements in y.