Is the following statement true or false? (If false, give the correct statement) 1) Given any input from an array, we can reconstruct a unique binary tree following the number labelling method (from top to down, left to right). 2) The worst case of Check whether a word exists in a text file using linear search from the beginning to the end is "The file is extremely big". 3) As long as the hash table is at least half empty, using quadratic probing can always find an empty slot for any key. 4) In a maze generated by Stack, there can be some rooms that are not reachable from the entrance