refactor: functions decs updated

src/algorithms/bwt/bwtDecode.ts

@@ -4,16 +4,16 @@ import { END_OF_STRING } from "./utils/constants";
 /**
  * Decodes a string that was encoded using the Burrows-Wheeler Transform (BWT).
  *
- * The function reconstructs the original string from its BWT representation by:
+
+ * 1. Create a createFrequencyMap for chars from input string.
+ *
+ * 2. Construct a mapping (`firstOccurrenceTable`) that indicates the starting position of each character in the sorted BWT string.
  *
- * 1. Building a frequency table of characters from the BWT string.
- * 2. Creating a table that maps each character to its first occurrence in the sorted version of the BWT string.
- * 3. Generating a `nextRow` table that helps in reconstructing the original string by indicating the position of each character in the sorted table.
- * 4. Using the `nextRow` table and starting from the provided index to rebuild the original string in reverse order.
+ * 3. Compute the index of each character in the BWT string as it appears in the sorted BWT string. 
  *
- * Instead of concatenating strings repeatedly, the function constructs the result using an array and then converts it to a string for improved performance.
+ * 4. Using the `charsIndexesInSortedInput` array, trace back from the given index to reconstruct the original string.
  *
- * @param {string} bwt - The Burrows-Wheeler Transform (BWT) encoded string to decode.
+ * @param {string} input - BWT encoded string to decode.
  * @param {number} index - The index of the original string in the sorted permutation table.
  * @returns {string} The decoded original string.
  */

src/algorithms/bwt/bwtEncode.ts

@@ -3,7 +3,7 @@ import { END_OF_STRING } from "./utils/constants";
 /**
  * Encodes a given string using the Burrows-Wheeler Transform (BWT).
  *
- * The function generates all cyclic permutations of the input string, sorts them
+ * The function virtualizes all cyclic permutations of the input string, sorts them
  * lexicographically, and constructs the BWT string from the last characters of each
  * permutation. It also returns the index of the original string in the sorted list of permutations.
  *
@@ -16,7 +16,7 @@ export function bwtEncode(input: string): { bwt: string; index: number } {
 
   const permutationsIndexes = Array.from({ length }, (_, i) => i);
 
-  // we're sorting all permutations
+  // sorting all permutations
   // using indexes
   // without creating actual strings
   permutationsIndexes.sort((a, b) => {

src/tools/getByteLength.ts

@@ -1,5 +1,10 @@
-export function getByteLength(str: string): number {
+/**
+ * Calculate byte size of a string
+ * @param {string} input - The string whose byte size is to be calculated.
+ * @returns {number} The number of bytes required to encode the string in UTF-8.
+ */
+export function getByteLength(input: string): number {
   const encoder = new TextEncoder();
-  const encoded = encoder.encode(str);
+  const encoded = encoder.encode(input);
   return encoded.length;
 }