Compute minimal operations and optimal server pairing

You are given two independent coding problems. ## Problem 1: Minimum range-increments to make an array nondecreasing Given an integer array `power` of length `n`. ### Operation In one operation, choose indices `l` and `r` with `0 <= l <= r < n`, and add `1` to every element in the contiguous subarray `power[l..r]`. ### Goal Make the final array **nondecreasing**, i.e. for all `i`: - `power[i] <= power[i+1]` Return the **minimum number of operations** required. ### Constraints (typical for OA) - `1 <= n <= 2 * 10^5` - `-10^9 <= power[i] <= 10^9` --- ## Problem 2: Pair servers to maximize total primary memory Given an integer array `memory` of length `m`, where each element is the memory capacity of one server. You may choose some servers and partition the chosen servers into **disjoint pairs**. For each pair, you must assign one server as `primary` and the other as `backup` such that: - `backup_memory >= primary_memory` Each server can be used **at most once** and cannot belong to multiple pairs. ### Goal Maximize the **sum of all primary memories** across all formed pairs. Return this maximum sum. (If you form no pairs, the sum is `0`.) ### Constraints (typical for OA) - `1 <= m <= 2 * 10^5` - `0 <= memory[i] <= 10^9`