Intuitive one to learn about Grundy basic :)
Now every pile becomes a game, so we need to use Sprague-Grundy Theory. Calculation is quite intuitive - and if you print them out, you will find these Grundy numbers loops by 9.
def firstMissing(s): ret = 0 while 1: if ret not in s: break else: ret += 1 return ret primes = [2,3,5,7,11,13] def grundy(v): if v <= 2: return 0 tmp = set([]) for p in primes: if p >= v: break else: tmp.add(grundy(v - p)) ret = firstMissing(tmp) grundySet[v] = ret return ret #################### def simpleGrundy(v): return [0,0,1,1,2,2,3,3,4][v%9] #################### T = int(input()) for _ in range(T): N = int(input()) A = map(int, input().split()) sg = map(simpleGrundy, A) ret = 0 for g in sg: ret ^= g print([‘Sandy‘,‘Manasa‘][ret!=0])
HackerRank "Manasa and Prime game"
原文：http://www.cnblogs.com/tonix/p/5186301.html