tvl-depot/scratch/facebook/moderate/rand7.py
William Carroll 09cd819a70 Include re-roll strategy for rand7
After seeing the solution that my book advocated, I implemented it using
recursion.
2020-11-14 17:36:04 +00:00

25 lines
543 B
Python

# Define a function, rand7, that generates a random number [0,7), using only
# rand5, which generates a random number [0,5).
import random
from collections import Counter
# Returns [0,4]
def rand5():
return random.randint(0,4)
# Return [0,6]
def rand7_a():
return sum(rand5() for _ in range(7)) % 7
# Return [0,6]
def rand7_b():
x = 5 * rand5() + rand5()
if x < 21:
return x % 7
return rand7_b()
c = Counter([rand7_a() for _ in range(100000)])
print(c)
c = Counter([rand7_b() for _ in range(100000)])
print(c)