Levenshtein distance

Benchmark created by Cesar Canassa on

Setup

function levenshtein_distance_a (a, b) {
    if(a.length == 0) return b.length; 
    if(b.length == 0) return a.length; 
  
    var matrix = [];
  
    // increment along the first column of each row
    var i;
    for(i = 0; i <= b.length; i++){
      matrix[i] = [i];
    }
  
    // increment each column in the first row
    var j;
    for(j = 0; j <= a.length; j++){
      matrix[0][j] = j;
    }
  
    // Fill in the rest of the matrix
    for(i = 1; i <= b.length; i++){
      for(j = 1; j <= a.length; j++){
        if(b.charAt(i-1) == a.charAt(j-1)){
          matrix[i][j] = matrix[i-1][j-1];
        } else {
          matrix[i][j] = Math.min(matrix[i-1][j-1] + 1, // substitution
                                  Math.min(matrix[i][j-1] + 1, // insertion
                                           matrix[i-1][j] + 1)); // deletion
        }
      }
    }
  
    return matrix[b.length][a.length];
  }
  
  
  function levenshtein_distance_b (s, t) {
      if (!s.length) return t.length;
      if (!t.length) return s.length;
  
      return Math.min(
          levenshtein_distance_b(s.substr(1), t) + 1,
          levenshtein_distance_b(t.substr(1), s) + 1,
          levenshtein_distance_b(s.substr(1), t.substr(1)) + (s[0] !== t[0] ? 1 : 0)
      );
  }

Test runner

Ready to run.

Testing in
TestOps/sec
algorithm B
levenshtein_distance_b('frankenstein', 'frankestein')
ready
algorithm A
levenshtein_distance_a('frankenstein', 'frankestein')
ready

Revisions

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