# Exclusion-2

 Author Sean Submission date 2016-08-23 10:46:45.930088 Rating 5642 Matches played 330 Win rate 55.76

Use rpsrunner.py to play unranked matches on your computer.

## Source code:

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

class ContextTree:
def __init__(self):
self.p_self = 0.0
self.p = 0.0
self.counts = [0, 0, 0]
self.children = [None, None, None]
def path(self, history):
nodes = []
i   = 0
end = min(len(history) - 1, 32)
while True:
nodes.append(self)
if i >= end:
break
x = history[i]
child = self.children[x]
if child is None:
child = ContextTree()
self.children[x] = child
nodes.append(child)
break
i += 1
self = child
return nodes

def update(path, c):
i = len(path) - 1
while i >= 0:
node = path[i]
b = node.counts[c] == 0
node.counts[c] += 1
if not b:
return
i -= 1

def predict(path):
counts = [1, 1, 1]
for node in path:
for i, n in enumerate(node.counts):
counts[i] += n
rt = 1.0 / sum(counts)
for i, n in enumerate(counts):
counts[i] *= rt
return counts

import collections
import random

R, P, S = range(3)
index = {"R": R, "P": P, "S": S}
name = ("R", "P", "S")
beat   = (P, S, R)
beaten = (S, R, P)
model = ContextTree()
history = collections.deque([])
output = random.choice(name)
else:
i = index[input]
j = index[output]
nodes = model.path(history)
history.appendleft(j)
history.appendleft(i)
update(nodes, i)
ps = predict(nodes)
scores = [0, 0, 0]
for _ in xrange(3):
x = 0
r = random.random()
for k, p in enumerate(ps):
x += p
if x >= r:
break
scores[beat[k]]   += 1
scores[beaten[k]] -= 1
m = max(scores)
output = name[random.choice([k for k, x in enumerate(scores) if x == m])]``````