CODE EXAMPLE FOR CSHARP

Maximum Points You Can Obtain from Cards

public class Solution 
{
    public int MaxScore(int[] c, int k) 
    {
        var wSize = c.Length - k;
        var sum = c.Sum();
        var res = 0;
        var temp = 0;
        var j = 0;
        for (var i = 0; i < c.Length; i++)
        {
            temp += c[i];
            if (i < wSize)
            {
                if(i==wSize-1)
                {
                    res = Math.Max(res, sum - temp);
                }
                continue;
            }
            temp -= c[j++];
            res = Math.Max(res, sum - temp);
        }
        return res;
    }
}