Python | Leetcode Python题解之第470题用Rand7()实现Rand10()
题目：
题解：
class Solution:
def rand10(self) -> int:
while True:
a = rand7()
b = rand7()
idx = (a - 1) * 7 + b
if idx <= 40:
return 1 + (idx - 1) % 10
a = idx - 40
b = rand7()
# get uniform dist from 1 - 63
idx = (a - 1) * 7 + b
if idx <= 60:
return 1 + (idx - 1) % 10
a = idx - 60
b = rand7()
# get uniform dist from 1 - 21
idx = (a - 1) * 7 + b
if idx <= 20:
return 1 + (idx - 1) % 10