You are given an array of integers (both positive and negative) Find the continuous sequence with the largest sum. Return the sum.

Design a method to find the frequency of occurrences of any given word in a book.

Imagine you have a square matrix, where each cell is filled with either black or white. Design an algorithm to find the maximum subsquare such that all four borders are filled with black pixels.

Find the smallest x + y + z with integers x > y > z > 0 such that x + y, x − y, x + z, x − z, y + z, y − z are all perfect squares.