Soluție HackerRank pentru Binomial Distribution #1, subdomeniul Probability, în Python 3. Include cerința formatată, exemple, explicația pașilor și cod…
- Problemă: Binomial Distribution #1
- Domeniu: Probability
- Limbaj: Python 3
Challenge: Binomial Distribution #1
Subdomeniu: Probability (probability)
Scor cont: 5.0 / 5
Submission status: Accepted
Submission score: 1.0
Submission ID: 464716729
Limbaj: python3
Link challenge: https://www.hackerrank.com/challenges/binomial-distribution-1/problem
Cerință
A blindfolded marksman finds that on the average he hits the target 4 times out of 5. If he fires 4 shots, what is the probability of
(a) more than 2 hits?
(b) at least 3 misses?
Submission Modes and Output Format
Your output should be two floating point/decimal numbers rounded to a scale of 3 decimal places (i.e., 1.234 format). There are two submission options:
1. Complete the challenge manually using pen and paper. Select *Plain Text* from the editor's language drop-down. Put the answer to question *(a)* on the first line and the answer to question *(b)* on the second line.
2. Hard-code the given parameters into a *Python* or *R* program that solves the probem, printing the solution to *(a)* on the first line and *(b)* on the second line.
Your answer should resemble something like:
<pre>
0.123
0.456
</pre>
(This is NOT the answer, just a demonstration of what the answering format should resemble).
Cod sursă
p = 4/5
n = 4
def binom(k, n, p):
res = 1
a = 1
for i in range(1, n+1):
a *= i
b = 1
for i in range(1, n-k+1):
b *= i
c = 1
for i in range(1, k+1):
c *= i
return a/b/c * p**k * (1-p)**(n-k)
def prob(k):
return binom(k, n, p)
if __name__ == '__main__':
result = prob(3) + prob(4)
print('%.3f' % result)
result = prob(0) + prob(1)
print('%.3f' % result)