# Newton's Bandit V2

This program has been disqualified.

 Author Sean Submission date 2016-02-25 01:49:24.729748 Rating 7026 Matches played 119 Win rate 71.43

## Source code:

``````if input == "":

import collections
import math
import random

gamma = random.gammavariate
sqrt = math.sqrt
log = math.log
exp = math.exp
R, P, S = 0, 1, 2
index = {"R": R, "P": P, "S": S}
beat = (P, S, R)
name = ("R", "P", "S")
third = 1.0 / 3.0

def psi(k, x):
u = (1.0 / k) * math.pow((2.5 * sqrt(1000 * k) / (-x)), 1.5)
return u

def phi(c, scores, k):
return sum(psi(k, s - c) for s in scores)

def dpsi(k, x):
return -(1054.39) / (x * x * x * sqrt(-sqrt(k) / x))

def dphi(c, scores, k):
return -sum(dpsi(k, s - c) for s in scores)

class MarkovTree:
def __init__(self, counts = None):
self.counts = [0.0 for _ in xrange(3)]
self.visits = [0.0 for _ in xrange(3)]
self.probs = [0.0 for _ in xrange(3)]
self.children = None

def scores(self):
counts = [gamma(x + 0.5, 1) for x in self.counts]
r, p, s = counts
return [s - p, r - s, p - r]

def update(self, h, i):
stop = False
leaf = False
for d, n in enumerate(h):
self.counts[i] += 1
if stop or d >= 64:
return
if self.children is None:
leaf = True
self.children = [None for _ in xrange(3)]
if self.children[n] is None:
self.children[n] = MarkovTree()
stop = True
self = self.children[n]

def predict(self, h):
scores = []
scores.extend(self.scores())
for n in h:
if self.children is None:
break
if self.children[n] is None:
break
self = self.children[n]
scores.extend(self.scores())
c0 = 360.0
c = c0
best = max(scores)
phi0 = 0
k = len(scores)
while True:
if c <= best:
c = best + 1
phi0 = phi(c, scores, k)
c = c - (phi0 - 1.0) / dphi(c, scores, k)
if abs(phi0 - 1) < 0.000001:
break
r = random.random()
x = 0
for i, s in enumerate(scores):
x += psi(k, s - c)
if r <= x:
return i % 3

tree = MarkovTree()
history = collections.deque([])
epoch = 1
v = 2.0 / 3
else:

epoch += 1
i = index[input]
j = index[output]

tree.update(history, i)

history.appendleft(i)
history.appendleft(j)
output = name[tree.predict(history)]``````