Version: v0.0.0-...-899dd15 Latest Latest Go to latest
Published: Sep 11, 2020 License: MIT

## README ¶

### 837. New 21 Game

#### 题目

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 the range [1, W], where W is an integer. Each draw is independent and the outcomes have equal probabilities.

Alice stops drawing numbers when she gets K or more points. What is the probabilitythat she has N or less points?

Example 1:

``````Input: N = 10, K = 1, W = 10
Output: 1.00000
Explanation:  Alice gets a single card, then stops.
``````

Example 2:

``````Input: N = 6, K = 1, W = 10
Output: 0.60000
Explanation:  Alice gets a single card, then stops.
In 6 out of W = 10 possibilities, she is at or below N = 6 points.
``````

Example 3:

``````Input: N = 21, K = 17, W = 10
Output: 0.73278
``````

Note:

1. 0 <= K <= N <= 10000
2. 1 <= W <= 10000
3. Answers will be accepted as correct if they are within 10^-5 of the correct answer.
4. The judging time limit has been reduced for this question.

## Documentation ¶ There is no documentation for this package.