RosettaCodeData/Task/Semordnilap/Eiffel/semordnilap-1.e
2015-11-18 06:14:39 +00:00

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Text

class
SEMORDNILAP
create
make
feature
make
--Semordnilaps in 'solution'.
local
count, i, middle, upper, lower: INTEGER
reverse: STRING
do
read_wordlist
create solution.make_empty
from
i := 1
until
i > word_array.count
loop
word_array [i].mirror
reverse := word_array [i]
from
lower := i + 1
upper := word_array.count
until
lower >= upper
loop
middle := (upper - lower) // 2 + lower
if reverse.same_string (word_array [middle]) then
count := count + 1
upper := 0
lower := 1
solution.force (word_array [i], count)
elseif reverse.is_less (word_array [middle]) then
upper := middle - 1
else
lower := middle + 1
end
end
if lower < word_array.count and then reverse.same_string (word_array [lower]) then
count := count + 1
upper := 0
lower := 1
solution.force (word_array [i], count)
end
i := i + 1
end
end
solution: ARRAY [STRING]
original_list: STRING = "unixdict.txt"
feature {NONE}
read_wordlist
-- Preprocessed word_array for finding Semordnilaps.
local
l_file: PLAIN_TEXT_FILE
wordlist: LIST [STRING]
do
create l_file.make_open_read_write (original_list)
l_file.read_stream (l_file.count)
wordlist := l_file.last_string.split ('%N')
l_file.close
create word_array.make_empty
across
1 |..| wordlist.count as i
loop
word_array.force (wordlist.at (i.item), i.item)
end
end
word_array: ARRAY [STRING]
end