From 7c60dee83b436e8e8a667bf9f191beced8de4fc3 Mon Sep 17 00:00:00 2001 From: Jack Sangdahl Date: Mon, 10 Mar 2025 00:36:13 -0600 Subject: chore: move cpp and rust code to directory --- other/new_21_game.cpp | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 other/new_21_game.cpp (limited to 'other/new_21_game.cpp') diff --git a/other/new_21_game.cpp b/other/new_21_game.cpp new file mode 100644 index 0000000..dc21609 --- /dev/null +++ b/other/new_21_game.cpp @@ -0,0 +1,40 @@ +// 837. New 21 Game +#include "leetcode.h" + +/* + * alice plays the following game, loosely based on the card game "21". alice + * starts with 0 points and draws numbers while she has less than 'k' points. + * during each draw, she gains an integer number of points randomly from range + * '[1, max_pts]', where 'max_pts' is an integer. each draw is independent and + * the outcomes have equal posibilities. alice stops drawing numbers when she + * gets 'k' or more points. return the probability that alice has 'n' or fewer + * points. answers within 10^-5 of the actual answer are considered accepted + */ + +class Solution { +public: + double new21Game(int n, int k, int max_pts) { + if (!k || n >= k + max_pts) + return 1.0; + vector dp(n + 1); + dp[0] = 1.0; + double sum = 1.0, ans = 0.0; + for (int i = 1; i <= n; ++i) { + dp[i] = sum / max_pts; + if (i < k) + sum += dp[i]; + else + ans += dp[i]; + if (i - max_pts >= 0) + sum -= dp[i - max_pts]; + } + return ans; + } +}; + +int main() { + Solution obj; + printf("%f\n", obj.new21Game(10, 1, 10)); // expect: 1.00000 + printf("%f\n", obj.new21Game(6, 1, 10)); // expect: 0.60000 + printf("%f\n", obj.new21Game(21, 17, 10)); // expect: 0.73278 +} -- cgit v1.2.3