Function that takes in two arrays of colors (strings) as input and returns a new array as output. We’ll call the two input arrays the items array and the order array. The strings in order are unique. The strings in items are not guaranteed to be unique. The output of the function should use the order array to determine the order of items. If a value does not appear in the order array, it should not be included in the output. You may assume both inputs are valid arrays.
Example input: items = [“red”, “blue”, “red”, “green”, “blue”] // Length = n order = [“blue”, “red”, “black”] // Length = k
Expected output: [“blue”, “blue”, “red”, “red”]
Time complexity: O(m) + O(M * Log M) time.