diff --git a/searches/jump_search.py b/searches/jump_search.py index 31a9656c5..3bc3c3780 100644 --- a/searches/jump_search.py +++ b/searches/jump_search.py @@ -4,14 +4,28 @@ This algorithm iterates through a sorted collection with a step of n^(1/2), until the element compared is bigger than the one searched. It will then perform a linear search until it matches the wanted number. If not found, it returns -1. + +https://en.wikipedia.org/wiki/Jump_search """ import math +from collections.abc import Sequence +from typing import Any, Protocol, TypeVar -def jump_search(arr: list, x: int) -> int: +class Comparable(Protocol): + def __lt__(self, other: Any, /) -> bool: + ... + + +T = TypeVar("T", bound=Comparable) + + +def jump_search(arr: Sequence[T], item: T) -> int: """ - Pure Python implementation of the jump search algorithm. + Python implementation of the jump search algorithm. + Return the index if the `item` is found, otherwise return -1. + Examples: >>> jump_search([0, 1, 2, 3, 4, 5], 3) 3 @@ -21,31 +35,36 @@ def jump_search(arr: list, x: int) -> int: -1 >>> jump_search([0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610], 55) 10 + >>> jump_search(["aa", "bb", "cc", "dd", "ee", "ff"], "ee") + 4 """ - n = len(arr) - step = int(math.floor(math.sqrt(n))) + arr_size = len(arr) + block_size = int(math.sqrt(arr_size)) + prev = 0 - while arr[min(step, n) - 1] < x: + step = block_size + while arr[min(step, arr_size) - 1] < item: prev = step - step += int(math.floor(math.sqrt(n))) - if prev >= n: + step += block_size + if prev >= arr_size: return -1 - while arr[prev] < x: - prev = prev + 1 - if prev == min(step, n): + while arr[prev] < item: + prev += 1 + if prev == min(step, arr_size): return -1 - if arr[prev] == x: + if arr[prev] == item: return prev return -1 if __name__ == "__main__": user_input = input("Enter numbers separated by a comma:\n").strip() - arr = [int(item) for item in user_input.split(",")] + array = [int(item) for item in user_input.split(",")] x = int(input("Enter the number to be searched:\n")) - res = jump_search(arr, x) + + res = jump_search(array, x) if res == -1: print("Number not found!") else: