search_frenzy.py

from collections import defaultdict
n_test_words = int(raw_input())

string_set = defaultdict(set)
substring_set = defaultdict(set)

for x in range(n_test_words):
    line = raw_input()

    for start in range(len(line)):
        for end in range(start+1, len(line)+1):
            substr = line[start:end]

            # we've already seen this substring, it's not unique
            if substr in substring_set:
                for string in substring_set[substr]:
                    # remove all string -> substr mappings
                    string_set[string].remove(substr)
                # remove all mappings of substr -> string, but leave
                # the key to check future duplicates
                substring_set[substr] = set()
            # unique substr found
            else:
                string_set[line].add(substr)
                substring_set[substr].add(line)


n_lookup_words = int(raw_input())

def min(values):
    min_val = None

    for val in values:
        if min_val == None:
            min_val = val
            
        if len(val) < len(min_val):
            min_val = val
        elif len(val) == len(min_val):
            for i in range(len(val)):
                if ord(val[i]) < ord(min_val[i]):
                    min_val = val
                    break
    return min_val

for x in range(n_lookup_words):
    key = raw_input().strip()

    if key not in string_set:
        print key, "ERROR"
    else:
        val = min(string_set[key])
        print key, val