n-Gram-Based Text Compression

Algorithm 2

Pseudocode of the four_gram_compression.

  input: The four-gram string, in this case is st4

  output: The encoded stream

() index = find(st4, four_gram_dict)

(2) if    then

()    force_trigram_compression(st3)

()    outputstring += compress(index, 4)

()    delete content of st4

() end

() else

()    st3 += first gram of st4

()    delete first gram of st4

()  if  number of grams of st3 = 3 then

()      trigram_compression(st3)

()  end

() end