algo4: dfs: n_queens: Revisited both
algo4: array: candy: Revisited and added O(1) space solution
algo4: dfs: restore_ip_addresses: Revisited
algo4: array: add_binary: Revisited
algo4: binarysearch: sqrt_x: Revisited
algo4: binarysearch: search_for_a_range: Revisited
algo4: binarysearch: search_in_rotated_sorted_array: Revisited
algo4: binarysearch: sqrt_x: Polished the solution
algo4: binarysearch: search_insert_position: Polished
algo4: binarysearch: search_in_a_sorted_2d_matrix: Revisited
algo4: binarysearch: search_original_starting_position_for_a_rotated_sorted_array: Revisted and stick to the template
algo4: binarysearch: Search peak element in a mountain array
algo4: comprehensive: Singleton
algo4: binarysearch: median_of_two_sorted_arrays: Revisited and added non-recursive solution
algo4: heap: Find kth frequent word in text
algo4: binarysearch: Search word in a sorted dictionary having empty string
algo4: binarysearch:  search_insert_position and search_the_first_larger_than_target: l be the return value