A. Turtle Puzzle: Rearrange and Negate
A. Turtle Puzzle: Rearrange and Negate time limit per test 2 seconds memory limit per test 256 megabytes You are given an array a � of n � integers. You must perform the following two operations on the array (the first, then the second): Arbitrarily rearrange the elements of the array or leave the order of its elements unchanged. Choose at most one contiguous segment of elements and replace the signs of all elements in this segment with their opposites. Formally, you can choose a pair of indices l , r � , � such that 1 ≤ l ≤ r ≤ n 1 ≤ � ≤ � ≤ � and assign a i = − a i � � = − � � for all l ≤ i ≤ r � ≤ � ≤ � (negate elements). Note that you may choose not to select a pair of indices and leave all the signs of the elements unchanged. What is the maximum sum of the array elements after performing these two operations (the first, then the second)? Input The first line of the input contains a single int...