Time Limit: 2 Seconds
Memory Limit: 65536 KB
A while ago it was quite cumbersome to create a message for the Short Message
Service (SMS) on a mobile phone. This was because you only have nine keys and
the alphabet has more than nine letters, so most characters could only be entered
by pressing one key several times. For example, if you wanted to type "hello"
you had to press key 4 twice, key 3 twice, key 5 three times, again key 5 three
times, and finally key 6 three times. This procedure is very tedious and keeps
many people from using the Short Message Service.
This led manufacturers of mobile phones to try and find an easier way to enter
text on a mobile phone. The solution they developed is called T9 text input.
The "9" in the name means that you can enter almost arbitrary words with just
nine keys and without pressing them more than once per character. The idea of
the solution is that you simply start typing the keys without repetition, and
the software uses a built-in dictionary to look for the "most probable" word
matching the input. For example, to enter "hello" you simply press keys 4, 3,
5, 5, and 6 once. Of course, this could also be the input for the word "gdjjm",
but since this is no sensible English word, it can safely be ignored. By ruling
out all other "improbable" solutions and only taking proper English words into
account, this method can speed up writing of short messages considerably. Of
course, if the word is not in the dictionary (like a name) then it has to be
typed in manually using key repetition again.
Figure 8: The Number-keys of a mobile phone.
More precisely, with every character typed, the phone will show
the most probable combination of characters it has found up to that point. Let
us assume that the phone knows about the words "idea" and "hello", with "idea"
occurring more often. Pressing the keys 4, 3, 5, 5, and 6, one after the other,
the phone offers you "i", "id", then switches to "hel", "hell", and finally
Write an implementation of the T9 text input which offers the most probable
character combination after every keystroke. The probability of a character
combination is defined to be the sum of the probabilities of all words in the
dictionary that begin with this character combination. For example, if the dictionary
contains three words "hell", "hello", and "hellfire", the probability of the
character combination "hell" is the sum of the probabilities of these words.
If some combinations have the same probability, your program is to select the
first one in alphabetic order. The user should also be able to type the beginning
of words. For example, if the word "hello" is in the dictionary, the user can
also enter the word "he" by pressing the keys 4 and 3 even if this word is not
listed in the dictionary.
The first line contains the number of scenarios.
Each scenario begins with a line containing the number w of distinct words in
the dictionary (0<=w<=1000). These words are given in the next w lines.
(They are not guaranteed in ascending alphabetic order, although it's a dictionary.)
Every line starts with the word which is a sequence
of lowercase letters from the alphabet without whitespace, followed by a space
and an integer p, 1<=p<=100, representing the probability of that word.
No word will contain more than 100 letters.
Following the dictionary, there is a line containing a single integer m. Next
follow m lines, each consisting of a sequence of at most 100 decimal digits
2-9, followed by a single 1 meaning "next word".
The output for each scenario begins with a line containing "Scenario #i:", where
i is the number of the scenario starting at 1.
For every number sequence s of the scenario, print one line for every keystroke
stored in s, except for the 1 at the end. In this line, print the most probable
word prefix defined by the probabilities in the dictionary and the T9 selection
rules explained above. Whenever none of the words in the dictionary match the
given number sequence, print "MANUALLY" instead of a prefix.
Terminate the output for every number sequence with a blank line, and print
an additional blank line at the end of every scenario.
Source: Northwestern Europe 2001