Python Triangle
def triangle(a: list[int]) -> int:
    a = sorted(a)
    c = len(a)
    if c < 3:
        return 0

    for i in range(c - 2):
        if a[i] > 0 and a[i] > (a[i + 2] - a[i + 1]):
            return 1

    return 0

This sorts the values and checks nearby triples, because a valid triangle only needs one local match after sorting.