3487. Maximum Unique Subarray Sum After Deletion

// Approach: If no duplicates, sum all positives; else take max element + all unique positives.
// Time: O(n) Space: O(n)

public class Solution
{
    public int MaxSum(int[] nums)
    {
        // Find the maximum value in the array
        int max = nums.Max();

        // If the maximum value is less than or equal to 0, return it
        if (max <= 0)
            return max;

        // Boolean array to keep track of numbers that have been added to the sum
        bool[] seen = new bool[201]; // Assuming numbers are within the range of 0 to 200
        int result = 0; // Initialize the sum

        // Iterate through each number in the array
        foreach (int num in nums)
        {
            // If the number is negative or has already been added, skip it
            if (num < 0 || seen[num])
                continue;

            // Add the number to the sum and mark it as seen
            result += num;
            seen[num] = true;
        }

        // Return the calculated sum
        return result;
    }
}