You are tasked with processing a string of plates (’*’) and candles (’|’) arranged on a table. For a set of queries, you must determine the number of plates that are enclosed by candles within specified substrings of the string.
You are given a string word consisting of lowercase English letters. Your task is to return the total sum of the number of vowels (‘a’, ’e’, ‘i’, ‘o’, and ‘u’) present in every possible substring of word. A substring is any contiguous sequence of characters in the word.
You are given two strings, word1 and word2, each of length n. The two strings are considered almost equivalent if the difference in frequency of each letter between word1 and word2 is at most 3. Return true if they are almost equivalent, or false otherwise.
Given an encoded string and the number of rows used to encode the original text, recover the original string. The encoded text is produced by filling a matrix in a slanted transposition cipher and reading it row by row.
You are given a string representing hamster positions. The string consists of ‘H’ for a hamster and ‘.’ for an empty space. You must place food buckets in empty positions such that all hamsters are fed. A hamster is fed if a food bucket is placed at one of its adjacent positions. Your task is to return the minimum number of food buckets required to feed all the hamsters. If it is impossible, return -1.