Delete divide_and_conquer/Suffix Array and LCP implementation.py

divide_and_conquer/Suffix Array and LCP implementation.py

@@ -1,88 +0,0 @@
-from typing import List
-
-
-class SuffixArray:
-    def __init__(self, text: str) -> None:
-        """
-        Initializes the class with the input text and builds the suffix and LCP arrays.
-        """
-        self.text = text
-        self.suffix_array = self.build_suffix_array()
-        self.lcp_array = self.build_lcp_array()
-
-    def build_suffix_array(self) -> List[int]:
-        """
-        Builds the suffix array for the input string.
-        Returns the suffix array (a list of starting indices of suffixes in sorted order).
-
-        Example:
-        >>> sa = SuffixArray("banana")
-        >>> sa.suffix_array
-        [5, 3, 1, 0, 4, 2]
-        """
-        n = len(self.text)
-        # Create a list of suffix indices sorted by the suffixes they point to
-        sorted_suffix_indices = sorted(
-            range(n), key=lambda suffix_index: self.text[suffix_index:]
-        )
-        return sorted_suffix_indices
-
-    def build_lcp_array(self) -> List[int]:
-        """
-        Builds the LCP (Longest Common Prefix) array for the suffix array.
-        LCP[i] gives the length of the longest common prefix of the suffixes
-        starting at suffix_array[i] and suffix_array[i-1].
-
-        Example:
-        >>> sa = SuffixArray("banana")
-        >>> sa.lcp_array
-        [0, 1, 3, 0, 0, 2]
-        """
-        n = len(self.text)
-        suffix_array = self.suffix_array
-        rank = [0] * n
-        lcp = [0] * n
-
-        # Build the rank array where rank[i] gives the position of the suffix starting at index i
-        for rank_index, suffix in enumerate(suffix_array):
-            rank[suffix] = rank_index
-
-        h = 0
-        for i in range(n):
-            if rank[i] > 0:
-                j = suffix_array[rank[i] - 1]  # Previous suffix in the sorted order
-                while (
-                    (i + h < n) and (j + h < n) and self.text[i + h] == self.text[j + h]
-                ):
-                    h += 1
-                lcp[rank[i]] = h
-                if h > 0:
-                    h -= 1  # Decrease h for the next suffix comparison
-        return lcp
-
-    def display(self) -> None:
-        """
-        Displays the suffix array and LCP array for the input string.
-
-        Example:
-        >>> sa = SuffixArray("banana")
-        >>> sa.display()
-        Suffix Array:
-        5: a
-        3: ana
-        1: anana
-        0: banana
-        4: na
-        2: nana
-
-        """
-        print("Suffix Array:")
-        for suffix_index in self.suffix_array:
-            print(f"{suffix_index}: {self.text[suffix_index:]}")
-
-
-# Example usage:
-if __name__ == "__main__":
-    text = "banana"
-    sa = SuffixArray(text)
-    sa.display()  # Contribution for Hacktoberfest 2024