Give you an integer array to return the length of the longest equal difference Subsequence in the array; Here is an array of integers and a sum of two integers. Please find and return the maximum sum of elements in two non overlapping subarrays; There is a pile of stones, each weighing a positive integer., After crushing in a regular order, at most one stone remains. Return the weight of this stone; Given the string S composed of Minuscule, the duplicate deletion operation will select two adjacent and identical letters, delete them, and return the final string. Some small operations bring great truth, and small things contain high wisdom. You need to uphold a humble attitude of learning in order to better ride the wind and waves.