13 prefix sums — DedSec Project
values = 4, 6, 2, 5 prefix = 0 for number in values: prefix.append(prefix -1 + number) def range_sum(left, right): if not (0 <= left <= right <= len(values)): raise ValueError('range')…
Αναφορά πηγαίου κώδικα
values = [4, 6, 2, 5]
prefix = [0]
for number in values: prefix.append(prefix[-1] + number)
def range_sum(left, right):
if not (0 <= left <= right <= len(values)): raise ValueError('range')
return prefix[right] - prefix[left]
assert range_sum(1, 3) == 8