File indexing completed on 2024-05-12 05:41:01

 #ifndef LEV_DISTANCE_H
 #define LEV_DISTANCE_H
 
 /**
  * Levenshtein Distance
  *
  * Code snippet taken from https://en.wikibooks.org/wiki/Algorithm_Implementation/Strings/Levenshtein_distance
  *
  * Licensed under CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0/)
  *
  * UNLESS OTHERWISE MUTUALLY AGREED TO BY THE PARTIES IN WRITING, LICENSOR OFFERS THE WORK AS-IS
  * AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE WORK, EXPRESS, IMPLIED,
  * STATUTORY OR OTHERWISE, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTIBILITY,
  * FITNESS FOR A PARTICULAR PURPOSE, NONINFRINGEMENT, OR THE ABSENCE OF LATENT OR OTHER DEFECTS
  * ACCURACY, OR THE PRESENCE OF ABSENCE OF ERRORS, WHETHER OR NOT DISCOVERABLE. SOME JURISDICTIONS
  * DO NOT ALLOW THE EXCLUSION OF IMPLIED WARRANTIES, SO SUCH EXCLUSION MAY NOT APPLY TO YOU.
  * EXCEPT TO THE EXTENT REQUIRED BY APPLICABLE LAW, IN NO EVENT WILL LICENSOR BE LIABLE TO YOU ON
  * ANY LEGAL THEORY FOR ANY SPECIAL, INCIDENTAL, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES ARISING
  * OUT OF THIS LICENSE OR THE USE OF THE WORK, EVEN IF LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY
  * OF SUCH DAMAGES.
  **/
 
 #include <algorithm>
 #include <numeric>
 #include <string>
 
 int levenshtein_distance(const std::string &s1, const std::string &s2)
 {
     // To change the type this function manipulates and returns, change
     // the return type and the types of the two variables below.
     int s1len = s1.size();
     int s2len = s2.size();
 
     auto column_start = (decltype(s1len))1;
 
     auto *column = new decltype(s1len)[s1len + 1];
     std::iota(column + column_start - 1, column + s1len + 1, column_start - 1);
 
     for (auto x = column_start; x <= s2len; x++) {
         column[0] = x;
         auto last_diagonal = x - column_start;
         for (auto y = column_start; y <= s1len; y++) {
             auto old_diagonal = column[y];
             auto possibilities = {column[y] + 1, column[y - 1] + 1, last_diagonal + (s1[y - 1] == s2[x - 1] ? 0 : 1)};
             column[y] = std::min(possibilities);
             last_diagonal = old_diagonal;
         }
     }
     auto result = column[s1len];
     delete[] column;
     return result;
 }
 
 #endif