REM Levenshtein distance
DECLARE FUNCTION LevDist(S$, T$) AS INTEGER
DECLARE FUNCTION MIN(A, B) AS INTEGER
PRINT "The Levenshtein distance..."
PRINT "between 'kitten' and 'sitting' is "; LevDist("kitten","sitting")
PRINT "between 'rosettacode' and 'raisethysword' is "; LevDist("rosettacode","raisethysword")
END

FUNCTION LevDist(S$, T$) AS INTEGER
N = LEN(T$): M = LEN(S$)
DIM D(0 TO N, 0 TO N)
FOR I = 0 TO M
  D(I, 0) = I
NEXT I
FOR J = 0 TO N
  D(0, J) = J
NEXT J
FOR J = 1 TO N
  FOR I = 1 TO M
    IF MID$(S$, I, 1) = MID$(T$, J, 1) THEN
      D(I, J) = D(I - 1, J - 1)
    ELSE
      D(I, J) = Min(D(I - 1, J) + 1, Min(D(I, J - 1) + 1, D(I - 1, J - 1) + 1))
    END IF
  NEXT I
NEXT J
LevDist = D(M, N)
END FUNCTION

FUNCTION Min(A, B) AS INTEGER
IF A < B THEN
  Min = A
ELSE
  Min = B
END IF
END FUNCTION