C# SOLUTION

int[] intArray = arr.ToArray(); if (arr.Count() == 1){ return "YES"; } int[] startEndSums = { 0 , intArray[..].Sum() };

    for (int i = 0; i < arr.Count(); i++){
        startEndSums[1] -= intArray[i];
        if (startEndSums[0] == startEndSums[1])
            return "YES";
        startEndSums[0] += intArray[i];
    }
    return "NO";