The document discusses the maximum subarray problem and different solutions to solve it. It defines the problem as finding a contiguous subsequence within a given array that has the largest sum. It presents a brute force solution with O(n2) time complexity and a more efficient divide and conquer solution with O(nlogn) time complexity. The divide and conquer approach recursively finds maximum subarrays in the left and right halves of the array and the maximum crossing subarray to return the overall maximum.