Dr. Astro Insky works at a radiotelescope centre. Recently, she noticed a very curious microwave
pulsing emission sent right from the centre of the galaxy. Is the emission transmitted by some
extraterrestrial form of intelligent life? Or is it nothing but the usual heartbeat of the stars?
You must help Dr. Insky to find out the truth by providing a tool to analyse bit patterns in the
files she records. Dr. Insky wants to find the patterns of length between (and including) A
and B that repeat themselves most often in the data file of each day. In each case, the greatest
N distinct frequencies (that is, number of occurrences) are sought. Pattern occurrences may overlap,
and only patterns that occur at least once are taken into account.
CONTACT.IN contains the data series, with the following format:
- First line - The integer A indicating the minimum pattern length.
- Second line - The integer B indicating the maximum pattern length.
- Third line - The integer N indicating the number of distinct frequencies.
- Fourth line - A sequence of 0 and 1 characters, terminated by a 2 character.
This asks for the top ten frequencies of patterns of length between two and four that occur in the bit
Note that the fourth line of the input file above appears split in order to fit herein. [Text has
been changed to single column for HTML format] In this example, pattern 100 occurs 12 times, and
pattern 1000 occurs 5 times. The most frequent pattern is 00.
A report in file
CONTACT.OUT with at most N lines, listing the at most N greatest frequencies and
corresponding patterns. The listing must be produced in decreasing order of pattern frequency, and
consists of lines formatted like
frequency pattern pattern … pattern
where frequency is the number of occurrences of the patterns that follow. The patterns in each line must appear in decreasing order of length. Patterns of equal length must be listed in reverse numerical order. In case there are less than N distinct frequencies, the output listing will have less than N lines.
For the sample input above, the output must be
15 10 01
11 001 000 11
7 1001 0010
6 0000 111
5 1000 110 011
4 1100 0011 0001
The input file may have up to 2 megabytes.
The parameters A, B and N are constrained by:
0 < N <= 20
0 < A <= B <= 12