Merkkijonot

import itertools

def optimize(str):
    combinations = itertools.combinations(list(str), 2) # TODO: Make me better?
    return ''.join(map(lambda x: x[0] == x[1] and '1' or '0', list(combinations)))

def solve(input):
    res = 0

    for index in input:
        data = input[index]
        if len(data) < 2:
            continue

        data = map(optimize, data)
        count = dict()
        for x in data:
            if x in count:
                res += count[x]
                count[x] += 1
            else:
                count[x] = 1

        # for x in list(set(data)):
        #     count = data.count(x)
        #     if count > 1:
        #         res += (count - 1) * count / 2

    return res

count = int(raw_input())
input = dict()
for x in range(0, count):
    curInput = raw_input()
    str_len = str(len(curInput))
    if not str_len in input:
        input[str_len] = list()

    input[str_len].append(curInput)

print(solve(input))

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 5

Group: 3

Verdict: ACCEPTED

Test 6

Group: 1, 2, 3

Verdict: ACCEPTED

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

Test 8

Group: 1, 2, 3

Verdict: ACCEPTED

Test 9

Group: 1, 2, 3

Verdict: ACCEPTED

Test 10

Group: 2, 3

Verdict: ACCEPTED

Test 11

Group: 2, 3

Verdict: ACCEPTED

Test 12

Group: 2, 3

Verdict: ACCEPTED

Test 13

Group: 2, 3

Verdict: ACCEPTED

Test 14

Group: 2, 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 17

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 18

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 19

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 20

Group: 1, 2, 3

Verdict: ACCEPTED

Test 21

Group: 1, 2, 3

Verdict: ACCEPTED

Test 22

Group: 1, 2, 3

Verdict: ACCEPTED

Test 23

Group: 1, 2, 3

Verdict: ACCEPTED

Test 24

Group: 1, 2, 3

Verdict: ACCEPTED