Subarray Sum Queries

There is an array consisting of n integers. Some values of the array will be updated, and after each update, your task is to report the maximum subarray sum in the array. Input The first input line contains integers n and m: the size of the array and the number of updates. The array is indexed 1,2,\ldots,n. The next line has n integers: x_1,x_2,\ldots,x_n: the initial contents of the array. Th