##

s1 = "a"

s2 = "ab"

from collections import Counter

class Solution:

def checkInclusion(self, s1, s2):

C = Counter(s1)

window = None

k=len(s1)

i=0

while i<len(s2)-k+1:

if i == 0:

window = Counter(s2[:len(s1)])

if C==window:

return True

print(window)

i+=1

else:

minus = {s2[i-1]:1}

plus = {s2[i+k-1]:1}

window -= minus

window += plus

print(window)

if C==window:

return True

i+=1

return False

Solution().checkInclusion(s1,s2)

##

Input="ABC"

from itertools import permutations

class Solution:

def numTilePossibilities(self, tiles):

res = []

for i in range(1, len(tiles)+1):

res += list(permutations(tiles,i))

return len(set(res))

Solution().numTilePossibilities(Input)

##

class Solution:

def generate(self, numRows):

n = 0

b = [1]

res = []

while n<numRows:

res.append(b)

b = [1] + [b[i]+b[i+1] for i in range(len(b)-1)] + [1]

n+=1

return res

Solution().generate(5)

##

S = "abbaca"

print(S)

##