From 5d449e06b0ccf99ad3d10e2ed2c37e6e902bab1c Mon Sep 17 00:00:00 2001 From: Jack Sangdahl Date: Sun, 17 Aug 2025 08:23:37 -0600 Subject: 837. new 21 game --- new_21_game.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) (limited to 'new_21_game.c') diff --git a/new_21_game.c b/new_21_game.c index 4076f33..a9a0f5a 100644 --- a/new_21_game.c +++ b/new_21_game.c @@ -1,37 +1,36 @@ // 837. New 21 Game -#include -#include +#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 + * '[1, maxPts]', where 'maxPts' 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 */ -double new21Game(int n, int k, int max_pts) { - if (!k || n >= k + max_pts) +double new21Game(int n, int k, int maxPts) { + if (!k || n >= k + maxPts) return 1.0; - double *dp = malloc((n + 1) * sizeof(double)); + double *dp = (double *)malloc((n + 1) * sizeof(double)); dp[0] = 1.0; double sum = 1.0, ans = 0.0; for (int i = 1; i <= n; ++i) { - dp[i] = sum / max_pts; + dp[i] = sum / maxPts; if (i < k) sum += dp[i]; else ans += dp[i]; - if (i - max_pts >= 0) - sum -= dp[i - max_pts]; + if (i - maxPts >= 0) + sum -= dp[i - maxPts]; } + free(dp); return ans; } int main() { - // new21Game(21,17,10); printf("%f\n", new21Game(10, 1, 10)); // expect: 1.00000 printf("%f\n", new21Game(6, 1, 10)); // expect: 0.60000 printf("%f\n", new21Game(21, 17, 10)); // expect: 0.73278 -- cgit v1.2.3