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main.py
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main.py
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from correct import correct_errors, is_valid
import bchlib
import random
import sys
def read_graph(filename):
f = open(filename, "r")
inv = list(map(int, f.readline().split()))
psl = list(map(int, f.readline().split()))
g = []
for line in f.readlines():
g.append(list(map(int, line.split())))
f.close()
n = len(g)
non_psl = []
j = 0
for i in range(n):
if psl[j] == i:
j += 1
else:
non_psl.append(i)
v_nums = dict()
for i in range(len(psl)):
v_nums[psl[i]] = i
return g, psl, non_psl, inv, v_nums
def bitflip(packet, i):
byte_num = i // 8
bit_num = i % 8
packet[byte_num] ^= (1 << bit_num)
p, q = 461, 29
t = 1839
g, psl, non_psl, inv, v_nums = read_graph("461_29.graph")
psl_set = set(psl)
n = q * (q * q - 1)
d = p + 1
data = bytearray(n * d // 16)
bch = bchlib.BCH(0x211, 27)
assert is_valid(data, bch, n, d, g, psl, non_psl, inv, v_nums)
l = 9000
r = 260000
def corrupt(packet, max_errs):
errs = random.randint(min(28, max_errs), min(d, max_errs))
v_num = random.randint(0, n - 1)
flips = random.sample(range(d), errs)
for flip in flips:
i = v_nums[v_num] * d + flip if v_num in psl_set else v_nums[g[v_num][flip]] * d + inv[flip]
bitflip(packet, i)
return errs
while r == None or r - l > 1:
m = l * 2 if r == None else (r + l) // 2
fl = True
print(f"{m} errors, does it work?")
for iter in range(500):
corrupted = data.copy()
errs_left = m
while errs_left > 0:
errs_left -= corrupt(corrupted, errs_left)
restored = correct_errors(corrupted, bch, n, d, g, psl, non_psl, inv, v_nums)
if data != restored:
fl = False
break
print(fl)
if fl:
l = m
else:
r = m