# switching17_fix3

 Author pyfex Submission date 2011-06-18 10:44:38.566410 Rating 7413 Matches played 5196 Win rate 77.6

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

## Source code:

``````# See http://overview.cc/RockPaperScissors for more information about rock, paper, scissors
# Switching with three different switching strategies

import random

if input == "":
hist = ""
opp_played = []
beat = {'P': 'S', 'S': 'R', 'R': 'P'}

score = {'RR': 0, 'PP': 0, 'SS': 0, 'PR': 1, 'RS': 1, 'SP': 1,'RP': -1, 'SR': -1, 'PS': -1,}
output = random.choice(["R", "P", "S"])

candidates = [output] * 6
# 1. Switch when lose or draw
# 2. switch when lose
# 3. Use best overall strategy
performance = [[(2,0)]*6, [(2,0)]*6, [0]*6]
main_performance = [0, 0, 0]
main_candidates = [output] * 3
indices = [0, 0, 0]
main_index = 0
else:
hist += output.lower()+input
opp_played.append(input)

for i, c in enumerate(candidates):
performance[0][i] = ({1:performance[0][i][0]+1, 0: 2, -1: 2}[score[c+input]],
performance[0][i][1]+score[c+input])
performance[1][i] = ({1:performance[1][i][0]+1, 0: performance[1][i][0], -1: 2}[score[c+input]],
performance[1][i][1]+score[c+input])
performance[2][i] += score[c+input]

indices[0] = performance[0].index(max(performance[0], key=lambda x: x[0]**3+x[1]))
indices[1] = performance[1].index(max(performance[1], key=lambda x: x[0]**3+x[1]))
indices[2] = performance[2].index(max(performance[2]))

for i, c in enumerate(main_candidates):
main_performance[i] += score[c+input]

main_index = indices[main_performance.index(max(main_performance))]

for length in range(min(14, len(hist)-2), 0, -2):
search = hist[-length:]
idx = hist.rfind(search, 0, -2)
if idx != -1:
my = hist[idx+length].upper()
opp = hist[idx+length+1]
candidates[0] = beat[opp]
candidates[1] = beat[beat[my]]
candidates[2] = opp
candidates[3] = my
candidates[4] = beat[beat[opp]]
candidates[5] = beat[my]
break
else:
output = random.choice(['R', 'P', 'S'])
candidates = [output] * 6

for i in range(3):
main_candidates[i] = candidates[indices[i]]

output = candidates[main_index]``````