Merkkijonot

def optimizeChar(str, index):
    res = ''

    str_len = len(str)
    for j in range(index + 1, str_len):
        res += str[index] == str[j] and '1' or '0'

    return res

def harmonic(data, index, stopAt):
    sorted = dict()
    for x in data:
        optimized = optimizeChar(x, index)
        
        if not optimized in sorted:
            sorted[optimized] = list()

        sorted[optimized].append(x)
    
    res = 0
    for x in sorted:
        data = sorted[x]
        sorted_len = len(data)
        if sorted_len > 1:
            if index == stopAt:
                res += (sorted_len - 1) * sorted_len / 2
                break

            count = harmonic(data, index + 1, stopAt)
            if count > 0:
                res += count

    return res

def solve(input):
    res = 0

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

        sorted = dict()
        for x in data:
            optimized = optimizeChar(x, 0)
            
            if not optimized in sorted:
                sorted[optimized] = list()

            sorted[optimized].append(x)
        
        for x in sorted:
            data = sorted[x]
            if len(data) > 1:
                count = harmonic(data, 1, int(index))
                if count > 0:
                    res += count

    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: ACCEPTED

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: ACCEPTED

Test 16

Group: 3

Verdict: ACCEPTED

Test 17

Group: 3

Verdict: ACCEPTED

Test 18

Group: 3

Verdict: ACCEPTED

Test 19

Group: 3

Verdict: ACCEPTED

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