[Solved] Python Code Fails

The thing is that range and xrange are written in C, hence they are prone to overflows. You need to write your own number generator to surpass the limit of C long.

def my_range(end):
    start = 0
    while start < end:
        yield start
        start +=1 


def conforms(k,s):
    k = k + 1
    if s.find("0" * k) == -1 and s.find("1" * k) == -1:
        return True
    else:
        return False


def brute(n,k,s):
    min_val = n + 1
    min_str = ""
    desired = long(s,2)
    for i in my_range(2 ** n):
        xor = desired ^ i # gives number of bit changes
        i_rep = bin(i)[2:].zfill(n) # pad the binary representation with 0s - for conforms()
        one_count = bin(xor).count('1')
        if one_count < min_val and conforms(k, i_rep):
            min_val = bin(xor).count('1')
            min_str = i_rep
    return (min_val,min_str)


T = 1
for i in range(T):
    words = [100, 1]
    start="00000001"
    sol = brute(words[0], words[1], start)
    print sol[0]
    print sol[1]