Merkkijonot

def harmonic(data, index, combinationIndex, stopAt):
    sorted = [[], []]
    for x in data:
        optimized = x[index] == x[combinationIndex] and 1 or 0
        # print('COMPARE FOR {}: {}, {} ({}, {})'.format(x, x[index], x[combinationIndex], index, combinationIndex))
 
        sorted[optimized].append(x)
    
    res = 0
    for data in sorted:
        sorted_len = len(data)
        if sorted_len > 1:
            if index == stopAt - 1 and combinationIndex == stopAt:
                res += (sorted_len - 1) * sorted_len / 2
                continue

            if combinationIndex == stopAt:
                count = harmonic(data, index + 1, index + 2, stopAt)
            else:
                count = harmonic(data, index, combinationIndex + 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

        res += harmonic(data, 0, 1, int(index) - 1)
 
    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: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 6

Group: 1, 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

Test 8

Group: 1, 2, 3

Verdict: ACCEPTED

Test 9

Group: 1, 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 10

Group: 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 11

Group: 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 12

Group: 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 13

Group: 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 14

Group: 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 15

Group: 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 16

Group: 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 17

Group: 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 18

Group: 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 19

Group: 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 20

Group: 1, 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 21

Group: 1, 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 22

Group: 1, 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...

Test 23

Group: 1, 2, 3

Verdict: ACCEPTED

Test 24

Group: 1, 2, 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 49, in <module>
    print(...