# switching18

This program has been disqualified.

 Author pyfex Submission date 2011-06-21 10:08:42.402251 Rating 7994 Matches played 2125 Win rate 77.41

## Source code:

# Switching with multiple different switching strategies

import random
import operator

if input == "":
hist = ""
my_stats = {'R':0, 'P':0, 'S': 0}
beat = {'P': 'S', 'S': 'R', 'R': 'P'}
cede = {'P': 'R', 'S': 'P', 'R': 'S'}

def shift(n, move):
return {0: move, 1:beat[move], 2:cede[move]}[n%2]

def unshift(n, move):
return {0: move, 1:cede[move], 2:beat[move]}[n%2]

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] * 150
# 1. Switch when lose or draw
# 2. switch when lose
# 3. Use best overall strategy
# 4. Use switching 16
# 5. Use rfind
# 6. Always play cede to my most played move (counter rndbeat)

performance = [[(2,0)]*6, [(2,0)]*6, [0]*6, [(2,0)]*150, 0, 0]
main_performance = [0, 0, 0, 0, 0, 0]
main_candidates = [output] * 6
indices = [0, 0, 0, 0] # only the first 4 main strats are switching strats
main_index = 0
wins = losses = ties = 0
else:
my_stats[output] += 1

sc = score[output+input]
if sc == 1:
wins += 1
elif sc == 0:
ties += 1
elif sc == -1:
losses += 1

hist += output.lower()+input

for i, c in enumerate(candidates[:6]):
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]

for i, c in enumerate(candidates):
performance[3][i] = ({1:performance[3][i][0]+1, 0: 2, -1: 2}[score[c+input]],
performance[3][i][1]+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]))
indices[3] = performance[3].index(max(performance[3], key=lambda x: x[0]**3+x[1]))

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

main_index = 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] = cede[my]
candidates[2] = opp
candidates[3] = my
candidates[4] = cede[opp]
candidates[5] = beat[my]
for i, a in enumerate(candidates[:6]):
for offset in range(3):
candidates[6+24*i+offset*8] = shift(offset+wins, a)
candidates[6+24*i+offset*8+1] = shift(offset+wins+ties, a)
candidates[6+24*i+offset*8+2] = shift(offset+losses+ties, a)
candidates[6+24*i+offset*8+3] = shift(offset+losses, a)
candidates[6+24*i+offset*8+4] = unshift(offset+wins, a)
candidates[6+24*i+offset*8+5] = unshift(offset+wins+ties, a)
candidates[6+24*i+offset*8+6] = unshift(offset+losses+ties, a)
candidates[6+24*i+offset*8+7] = unshift(offset+losses, a)
main_candidates[4] = beat[opp]
break
else:
output = random.choice(['R', 'P', 'S'])
candidates = [output] * 150

for i in range(4):
main_candidates[i] = candidates[indices[i]]

main_candidates[5] = cede[max([e for e in my_stats.items()], key=operator.itemgetter(1))[0]]
output = main_candidates[main_index]