train.py

#! /usr/bin/python 
#https://code.google.com/codejam/contest/3004486/dashboard#s=p1

import sys 

def deduplicate(train):
    prev = train[0]
    deduped = [prev]
    for i in range(1, len(train)):
        if train[i] != prev:
            prev = train[i]
            deduped.append(train[i])
    return "".join(deduped)

def adjacentyCheck(train):
#    train = deduplicate(train)
    m = {}
    for c in train:
        if c in m:
            return False
        m[c]=1
    return True    
    

def main():
    T = int(raw_input())
    for t in range(T):
        number_of_trains = int(raw_input())
        trains = raw_input().split(" ")
        for train in range(len(trains)):
            trains[train] = deduplicate(trains[train])
            inside = []
            if len(trains[train]) > 2:
                if trains[train][0] == trains[train][-1]:
                    print t
                inside.append(trains[train][1:-1])
            if not adjacentyCheck("".join(inside)):
                print t
#        print trains
        

main()