1. Given two strings a and b, merge the strings so that the letters are added in alternating order starting with string a. If one string is longer than the other, then append the letters to the end of the merged string. ex. "abcd", "efghi" -> "aebfcgdhi" ex. "", "abcd" -> "abcd" ex. "abcdefg", "zxy" -> "azbxycdefg" Pretty easy. Just interlace them like a merge sort. 2. Rotate matrix around diagonals. Given an n x n matrix M, where n is odd and n > 1, and an integer k, rotate M counterclockwise k times which are not on the main diagonal or on the diagonal from the top right to the bottom left. Return the new matrix. 3. Given a list of strings string_list and a list of words words, determine whether each word in words can be formed as a concatenation of consecutive strings in string_list starting with index 0. ex. word = "oneTwoThree", string_list = ["one", "Three", "Two"] is false because the words aren't consecutive in string_list ex. word = "one", string_list = ["one", "Three", "Two"] is True because the concatenation stops at the first index in string_list ex. word = "one", string_list = ["One", "one", "Two"] is False because the concatenation doesn't start at 0. 4. Given two arrays a and b of equal length, the absolute sum difference is the sum Math.abs(a[i] - b[i]). Replace one number in a with any number in a to minimize the absolute sum difference.