research/defrag/defrag_sim.py
2018-09-24 10:52:49 -04:00

84 lines
2.3 KiB
Python

import random, math
def mk_initial_balances(accts, coins):
o = []
for i in range(accts):
o.extend([i] * random.randrange((coins - len(o)) * 2 // (accts - i)))
o.extend([accts-1] * (coins - len(o)))
return o
def fragments(coins):
o = 0
for i in range(1, len(coins)):
if coins[i] != coins[i-1]:
o += 1
return o
def xfer(coins, frm, to, value):
coins = coins[::]
pos = 0
while pos < len(coins) and value > 0:
if coins[pos] == frm:
coins[pos] = to
value -= 1
pos += 1
return coins
def unscramble(coins, c1, c2):
coins = coins[::]
k1 = coins.count(c1)
pos = 0
while pos < len(coins):
if coins[pos] in (c1, c2):
coins[pos] = c1 if k1 > 0 else c2
if coins[pos] == c1:
k1 -= 1
pos += 1
return coins
def multi_unscramble(coins, addrs):
coins = coins[::]
ks = [coins.count(c) for c in addrs]
pos = 0
at = 0
while pos < len(coins):
if coins[pos] in addrs:
coins[pos] = addrs[at]
ks[at] -= 1
if ks[at] == 0:
at += 1
pos += 1
return coins
def unscramble_swap_strategy(coins, rounds):
for i in range(rounds):
c1, c2 = sorted([random.randrange(max(coins)+1) for _ in range(2)])
coins = unscramble(coins, c1, c2)
return coins
def run_with_unscrambling(coins, rounds):
M = max(coins) + 1
for i in range(rounds):
c1, c2 = [random.randrange(M) for _ in range(2)]
value = int(coins.count(c1) ** random.random())
coins = xfer(coins, c1, c2, value)
coins = unscramble(coins, min(c1, c2), max(c1, c2))
return coins
def run_with_unscramble_online(coins, rounds):
M = max(coins) + 1
for i in range(rounds):
c1, c2 = [random.randrange(M) for _ in range(2)]
value = int(coins.count(c1) ** random.random())
coins = xfer(coins, c1, c2, value)
if random.random() < 1:
cx = sorted([random.randrange(M) for _ in range(5)])
coins = multi_unscramble(coins, cx)
return coins
c = mk_initial_balances(200, 10000)
# random.shuffle(c)
# c = unscramble_swap_strategy(c, 20000)
c = run_with_unscramble_online(c, 10000)
print(fragments(c))