Задача A. Слово из кубиков ≡

Автор:A. Klenin   Ограничение времени:8 сек
Входной файл:input.txt   Ограничение памяти:4 Мб
Выходной файл:output.txt  

Условие

Имеется N кубиков, на гранях которых написаны буквы. Требуется определить, можно ли из этих кубиков составить данное слово длиной K символов, и если да, то вывести номера использованных кубиков. При этом каждый кубик можно использовать только один раз. Если решений несколько, выдать любое из них.

Формат входного файла

В первой строке входного файла содержится количество кубиков N. Во второй строке — слово, в следующих N строках — по шесть символов без разделителей, определяющих буквы на гранях кубиков. (Порядок букв не имеет значения).

Формат выходного файла

Выходной файл должен содержать последовательность из K различных целых чисел от 1 до N, задающих номера кубиков для каждой буквы слова, начиная с первой. Если решения нет, выходной файл должен содержать единственное число 0.

Ограничения

1 ≤ N, K ≤ 12.

Примеры тестов

№ Входной файл (input.txt) Выходной файл (output.txt)
1 
5
TEST
ABCDAB
TTTTTT
STSTST
CREATE
ERRORS
 
2 5 3 4

Problem B. Network Saboteur ≡

Author:Far-Eastern Subregional   Time limit:3 sec
Input file:input.txt   Memory limit:8 Mb
Output file:output.txt  

Statement

A university network is composed of N computers. System administrators gathered information on the traffic between nodes, and carefully divided the network into two subnetworks in order to minimize traffic between parts.

A disgruntled computer science student Vasya, after being expelled from the university, decided to have his revenge. He hacked into the university network and decided to reassign computers to maximize the traffic between two subnetworks.

Unfortunately, he found that calculating such worst subdivision is one of those problems he, being a student, failed to solve. So he asks you, a more successful CS student, to help him.

The traffic data are given in the form of matrix C, where Cij is the amount of data sent between ith and jth nodes (Cij = Cji, Cii = 0). The goal is to divide the network nodes into the two disjointed subsets A and B so as to maximize the sum of all Cij, where i belongs to A, and j belongs to B.

Input file format

The first line of input file contains a number of nodes N. The following N lines, containing N space-separated integers each, represent the traffic matrix C.

Output file format

Output file must contain a single integer - the maximum traffic between the subnetworks.

Constraints

2 ≤ N ≤ 20; 0 ≤ Cij ≤ 10000.

Sample tests

No. Input file (input.txt) Output file (output.txt)
1 
3
0 50 30
50 0 40
30 40 0

90

Problem C. Hot-keys ≡

Author:A. Klenin   Time limit:5 sec
Input file:input.txt   Memory limit:64 Mb
Output file:output.txt  

Statement

When designing dialog forms for interactive programs, it is important to assign hot-keys (known also as accelerator keys) to each dialog element, so as to facilitate keyboard input.

For better mnemonics, hot-keys are assigned based on the letters of dialog elements' captions, usually favoring letters near the beginning of caption. Manual hot-keys distribution can be tedious and error-prone, as one must be careful not to assign same letter to different elements.

Your program will be given a list of captions. It must assign unique hot-keys to as many captions of possible. Each assigned hot-key must be a letter from the corresponding caption.

For each hot-key, position is the leftmost occurrence of the hot-key letter in the corresponding caption. From all solutions with the same numbers of hot-keys, your program must choose the one with minimal sum of hot-key positions. If there is still more than one optimal solution, output any of them.

Input file format

Input file contains number of captions N followed by N lines with captions.

Output file format

Output file must contain N lines with the same captions as in input. In those captions which have hot-key assigned, leftmost occurrence of hot-key letter must be preceded with '&' (ASCII 38).

Constraints

1 ≤ N ≤ 10, all captions are from 1 to 10 characters in length and consist of small Latin letters.

Sample tests

No. Input file (input.txt) Output file (output.txt)
1 
3
yes
no
cancel
 
&yes
&no
&cancel
2 
4
abc
bca
acb
aaaa
 
&abc
&bca
a&cb
aaaa
0.034s 0.005s 11