Java code

public static List maxSubarray(List arr) { if (arr.size() == 1) { return List.of(arr.get(0), arr.get(0)); }

    if (arr.stream().allMatch(i -> i < 0)) {
        int maxNegative = arr.stream().mapToInt(Integer::intValue).max().orElse(Integer.MIN_VALUE);
        return List.of(maxNegative, maxNegative);
    }

    int currentValue = 0;
    int maxValue = 0;

    for (int i = 0; i < arr.size(); i++) {
        int value = arr.get(i);
        if (value >= 0) {
            currentValue += value;
        } else {
            if (currentValue + value > 0) {
                currentValue += value;
            } else {
                currentValue = Math.max(currentValue, value);
                currentValue = 0;
            }
        }

        maxValue = Math.max(maxValue, currentValue);
    }

    return List.of(maxValue, arr.stream()
            .filter(value -> value > 0)
            .mapToInt(Integer::intValue)
            .sum());
}