Experiments with Knuth's 5,757 five letter words. https://charlesreid1.com/wiki/Five_Letter_Words
選択できるのは25トピックまでです。 トピックは、先頭が英数字で、英数字とダッシュ('-')を使用した35文字以内のものにしてください。
Charles Reid b45fda3052
Merge pull request #1 from charlesreid1/try-trie-tree
output Add near palindrome output, and fix palindrome pairs to exclude palindromes 2年前
.gitignore adding memo to gitignore. 2年前
LICENSE updating license, readme, and adding words. 2年前
README.md update readme and descriptions 1年前
diff_by_n.py print more info 1年前
diff_by_one_fixed.py update diff_by_ scripts and descriptions in readme 1年前
distinct.py Make distinct.py more efficient: one loop over words. 2年前
euclidean_distance.py reverse order of printed distances 2年前
get_words.py adding get words function. 2年前
letter_coverage.py updating final print statement in both letter coverages 2年前
letter_coverage_dbg.py updating final print statement in both letter coverages 2年前
lexico.py fix comments. 2年前
near_palindromes.py clarify palindrome checks 2年前
palindromes.py clarify palindrome checks 2年前
reverse_lexico.py fix comments. 2年前
sgb-words.txt Adding Stanford GraphBase list of five-letter words 2年前
stats.py remove particular bigrams 2年前
tries.py switch function 1年前



This repository contains Donald Knuth’s GraphBase list of five-letter words,
as well as scripts to run various combinatoric experiments,
graph algorithms, and other algorithms to explore the
relationships among these words.

The list of words comes from [1] and is in the public domain.

Get Words

A Python program that contains a method for getting all of the five letter words from a file,
and that’s about it.

Warm Up Exercises

Exercises 26-37 of Knuth’s Volume 4 Fascile 0 are intended as a warm up to get to know
the SGB five letter word list. Solutions to these exercises are listed below.

distinct.py- computes the number of SGB words containing exactly k distinct letters.

diff_by_one_fixed.py - (fixed 2019-03-09) computes the number of words in the SGB
that are off by a single letter in each position. An example is rover and spuds.
Each corresponding letter is only different by one: r -> s, o->p, and so on.
This uses recursive backtracking to generate possible matches for each word, and
uses a hash table to check for their existence in the original word set.

There are 38 such pairs in the SGB.

Also see Five Letter Words
on the charlesreid1.com wiki.

diff_by_n_fixed.py - (added 2019-03-10.) using the corrected approach (above) to
computing differences by 1, this generalizes the calculation to words that are different
by a distance d for each letter position.

Also see Five Letter Words: Part 4: Revisiting Diff by One
(blog post) on charlesreid1.github.io.

euclidean_distance.py - computes the euclidean distance between two words. This uses
the traditional Euclidean distance definition but reinterprets distance to mean edit distance.

lexico.py - find words that are sorted by lexicographic order (front to back, a-z).

palindromes.py - look for five letter words that are either a palindrome, or a palindrome pair.


diff_by_n.py - computes words in SGB that have an edit distance of n.

reverse_lexico.py - variation on lexico.py that finds words whose letters are in
reverse lexicographic order.

Letter Coverage

letter_coverage.py - computes coverage of the alphabet (minimum number of words required
to provide X letters of the alphabet)

Knuth mentions, in the text, a couple of facts about how many words cover how much
of the alphabet. We authored a dynamic program to compute precisely this - given a
number of letters N from the alphabet, this program computes the minimum number of
words it takes to cover all N letters.

Also see Letter Coverage
page on the charlesreid1.com wiki.


  1. Knuth, Donald. The Stanford GraphBase: A Platform for Combinatorial Computing. New York: ACM Press, 1994.