题解 | #increment of coins#
擅长解密的小红同学
https://ac.nowcoder.com/acm/contest/32282/A
期望dp
感兴趣可以做一下高德纳的厕纸问题
[1] Donald E. Knuth. The American Mathematical Monthly. Vol. 91, No. 8 (Oct., 1984), pp. 465-470
# dp,没啥说的
from functools import *
@lru_cache(maxsize=None)
def func(a,b,c):
if a==100 or b==100 or c==100:
return 0
else:
return 1+a/(a+b+c)*func(a+1,b,c)+b/(a+b+c)*func(a,b+1,c)+c/(a+b+c)*func(a,b,c+1)
a,b,c=map(int,input().split())
print(func(a,b,c))