49 lines
1.3 KiB
Python
49 lines
1.3 KiB
Python
"""
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Jump search algorithm iterates through a sorted list with a step of n^(1/2),
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until the element compared is bigger than the one searched.If the item is not
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in the particular step, it shifts the entire step.
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It will then perform a linear search on the step until it matches the target.
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If not found, it returns -1.
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Time Complexity: O(√n)
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Space Complexity: O(1)
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"""
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import math
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def jump_search(arr: list, x: int) -> int:
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n = len(arr)
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step = int(math.floor(math.sqrt(n)))
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prev = 0
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while arr[min(step, n) - 1] < x:
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prev = step
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step += int(math.floor(math.sqrt(n)))
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if prev >= n:
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return -1
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while arr[prev] < x:
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prev = prev + 1
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if prev == min(step, n):
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return -1
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if arr[prev] == x:
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return prev
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return -1
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def check_sort(test: list) -> bool:
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"""checks whether the given list is sorted or not."""
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if sorted(test) == test:
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return True
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else:
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return False
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if __name__ == "__main__":
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arr = [0, 1, 2, 8, 13, 17, 19, 25, 31, 32, 42]
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target = 25
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if check_sort(arr):
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res = jump_search(arr, target)
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if res == -1:
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print("Number not found!")
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else:
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print(f"Number {target} is at index {res}")
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else:
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print("Given list is not sorted!") |