text: const calculateDistance = (a, b) => {
    if (a.length === 0) return b.length
    if (b.length === 0) return a.length
  
    const matrix = []
  
    // increment along the first column of each row
    let i
    for (i = 0; i <= b.length; i++) {
      matrix[i] = [i]
    }
  
    // increment each column in the first row
    let 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]
  }
  
  module.exports = calculateDistance
  