[PR #927] Rewrite the trie example #1461

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claunia · 2026-01-29T15:20:58Z

claunia commented

2026-01-29 15:20:58 +00:00

Original Pull Request: https://github.com/TheAlgorithms/C/pull/927

State: closed
Merged: Yes

The trie example had some issues;

It did not follow the code convention in CONTRIBUTING.md
The createTrieNode used an inefficient zeroing method (looping over
the entries) which also does not zero out holes in the structure (e.g.
an alternative would be to use "*node = &(TrieNode){0}", but calloc
does all that anyway
It used an inefficient and clumsy printArray method
It used strlen inside the algorithm; this new method could get rid of
any strlen/strnlen usage (inserts/searches could be sanitized by
snprintf)
This version can allow for a custom mapping function, e.g. if NULL is
a valid separator (say that you want a trie for certain binary
packages)
The previous version actually contained out-of-bounds array indexing;
there were no checks for out-of-bound indexing and words in the word
list did contain out of bounds words. It's a surprise it was working
so well.
This version just returns 'int' to allow for error checks (instead of
a printf inside the algorithm), and uses double pointers for return
values (good practice)
The usage example contained unnecessary mallocs, switched that out for
scanf. The example is just an example after all, in real applications
you'd have better input sanitazion.

Description of Change

References

Checklist

Added description of change
Added file name matches File name guidelines
Added tests and example, test must pass
Relevant documentation/comments is changed or added
PR title follows semantic commit guidelines
Search previous suggestions before making a new one, as yours may be a duplicate.
I acknowledge that all my contributions will be made under the project's license.

Notes:

**Original Pull Request:** https://github.com/TheAlgorithms/C/pull/927 **State:** closed **Merged:** Yes --- The trie example had some issues; * It did not follow the code convention in CONTRIBUTING.md * The createTrieNode used an inefficient zeroing method (looping over the entries) which also does not zero out holes in the structure (e.g. an alternative would be to use "*node = &(TrieNode){0}", but calloc does all that anyway * It used an inefficient and clumsy printArray method * It used strlen inside the algorithm; this new method could get rid of any strlen/strnlen usage (inserts/searches could be sanitized by snprintf) * This version can allow for a custom mapping function, e.g. if NULL is a valid separator (say that you want a trie for certain binary packages) * The previous version actually contained out-of-bounds array indexing; there were no checks for out-of-bound indexing and words in the word list did contain out of bounds words. It's a surprise it was working so well. * This version just returns 'int' to allow for error checks (instead of a printf inside the algorithm), and uses double pointers for return values (good practice) * The usage example contained unnecessary mallocs, switched that out for scanf. The example is just an example after all, in real applications you'd have better input sanitazion. #### Description of Change  #### References  #### Checklist  - [x] Added description of change - [x] Added file name matches [File name guidelines](https://github.com/TheAlgorithms/C/blob/master/CONTRIBUTING.md#File-Name-guidelines) - [ ] Added tests and example, test must pass - [x] Relevant documentation/comments is changed or added - [ ] PR title follows semantic [commit guidelines](https://github.com/TheAlgorithms/C/blob/master/CONTRIBUTING.md#Commit-Guidelines) - [x] Search previous suggestions before making a new one, as yours may be a duplicate. - [x] I acknowledge that all my contributions will be made under the project's license. Notes:  <a href="https://gitpod.io/#https://github.com/TheAlgorithms/C/pull/927"><img src="https://gitpod.io/button/open-in-gitpod.svg"/></a>

claunia added the pull-request label 2026-01-29 15:20:58 +00:00

claunia referenced this issue

2026-01-29 15:28:10 +00:00

[PR #1461] [CLOSED] Fork #2057

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Reference: starred/C#1461