sum tail recursive - java

    // for
    public static int sum(int n) {
        int sum = 0;

        for (int i = 1; i <= n; ++i) {
            sum += i;
        }

        return sum;
    }

    // recursive
    public static int sumResursive(int n) {
        if (n < 1) {
            return n;
        }

        return n + sumResursive(n - 1);
    }

    // tail recursive
    public static int sumTailRecursie(int n, int sum) {
        if (n < 1) {
            return sum;
        }

        return sumTailRecursie(n - 1, n + sum);
    }