From 3da098ba6f5327df8d6648183d8bc229187bbd86 Mon Sep 17 00:00:00 2001 From: Hariharan Date: Tue, 15 Oct 2024 19:59:26 +0530 Subject: [PATCH] Update BinarySearch_on_Sorted_2D_Array.py --- sorts/BinarySearch_on_Sorted_2D_Array.py | 50 ++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/sorts/BinarySearch_on_Sorted_2D_Array.py b/sorts/BinarySearch_on_Sorted_2D_Array.py index e69de29bb..fcce1d795 100644 --- a/sorts/BinarySearch_on_Sorted_2D_Array.py +++ b/sorts/BinarySearch_on_Sorted_2D_Array.py @@ -0,0 +1,50 @@ +def binary_search_2d(matrix: list[list[int]], target: int) -> tuple[int, int]: + """ + Searches for a target value in a 2D sorted array. + + The matrix is sorted such that each row is in ascending order, and the + first element of each row is greater than the last element of the previous row. + + :param matrix: A 2D list of integers sorted in ascending order. + :param target: The integer value to search for. + :return: A tuple (row_index, col_index) if found, otherwise (-1, -1). + + Examples: + >>> binary_search_2d([[1, 3, 5], [7, 9, 11], [12, 13, 15]], 9) + (1, 1) + >>> binary_search_2d([[1, 3, 5], [7, 9, 11], [12, 13, 15]], 4) + (-1, -1) + """ + if not matrix or not matrix[0]: + return -1, -1 + + rows, cols = len(matrix), len(matrix[0]) + left, right = 0, rows * cols - 1 + + while left <= right: + mid = left + (right - left) // 2 + mid_value = matrix[mid // cols][mid % cols] + + if mid_value == target: + return mid // cols, mid % cols + elif mid_value < target: + left = mid + 1 + else: + right = mid - 1 + + return -1, -1 + + +if __name__ == "__main__": + import doctest + + doctest.testmod() + + # Example usage + matrix = [[1, 3, 5], [7, 9, 11], [12, 13, 15]] + target = 9 + result = binary_search_2d(matrix, target) + if result == (-1, -1): + print(f"{target} was not found in the matrix.") + else: + print(f"{target} was found at position {result} in the matrix.")