# 2327. Number of People Aware of a Secret """ on day 1, one person discovers decret. you are given an integer 'delay' which means that each person will share the secret with a new person every day starting from 'delay' days after discovering the secret. you are also given an integer 'forget', which means that each person will forget the secret 'forget' days after discovering it. a person cannot share the secret on the same day they forgot it, or any day afterwards. given an integer 'n', return the number of people who know the secret at the end of day 'n'. since the answer may be very large, return it modulo 10^9+7. """ class Solution(object): def peopleAwareOfSecret(self, n, delay, forget): """ :type n: int :type delay: int :type forget: int :rtype: int """ dp = [1] + [0] * forget share, mod = 0, 10**9 + 7 for i in range(1, n): dp[i % forget] = share = ( share + dp[(i - delay) % forget] - dp[i % forget] ) % forget return sum(dp) % mod if __name__ == "__main__": obj = Solution() print(obj.peopleAwareOfSecret(6, 2, 4)) print(obj.peopleAwareOfSecret(4, 1, 3))