Solve four OA coding problems

The online assessment reportedly contained four coding problems:

1. Compare negative and positive counts
   Given a sorted integer array nums in nondecreasing order, return the larger of:
   • the number of elements less than 0
   • the number of elements greater than 0
   Elements equal to 0 should not be counted in either group.
2. Reach a destination with charging stations
   A drone must travel target units of distance. It starts with startCharge units of battery, and it consumes 1 unit of battery per unit of distance traveled. Along the route, stations[i] = [position_i, charge_i] describes a charging station at distance position_i from the start that can provide charge_i additional battery units. The stations are sorted by position. Return the minimum number of charging stops needed to reach the destination, or -1 if the destination cannot be reached.
3. Count objects placed on a grid
   You are given an m x n grid of characters 'X' and '.' . Each object is formed by one or more contiguous 'X' cells placed either horizontally in one row or vertically in one column. Different objects are separated by at least one '.' cell, so no two distinct objects touch horizontally or vertically. Return the total number of objects in the grid.
4. Find the longest consecutive-value run
   Given an unsorted integer array nums , return the length of the longest set of consecutive integer values that appears in the array. The values do not need to be adjacent in the original array. Aim for an O(n) solution.