52 lines
1.2 KiB
Python
52 lines
1.2 KiB
Python
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# Python program to implement
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# interpolation search with recursion
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# If x is present in arr[0..n-1], then
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# returns index of it, else returns -1.
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# Time complexity is O(log(log(n)) in
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# average case. O(n) in the worst case.
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def interpolationSearch(arr, lo, hi, x):
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# Since array is sorted, an element present
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# in array must be in range defined by corner
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if (lo <= hi and x >= arr[lo] and x <= arr[hi]):
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# Probing the position while keeping
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# uniform distribution in mind.
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pos = lo + ((hi - lo) // (arr[hi] - arr[lo]) *
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(x - arr[lo]))
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# Condition of target found
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if arr[pos] == x:
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return pos
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# If x is larger, x is in right subarray
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if arr[pos] < x:
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return interpolationSearch(arr, pos + 1,hi, x)
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# If x is smaller, x is in left subarray
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if arr[pos] > x:
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return interpolationSearch(arr, lo,pos - 1, x)
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return -1
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# Driver code
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# Array of items in which
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# search will be conducted
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arr = [10, 12, 13, 16, 18, 19, 20,
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21, 22, 23, 24, 33, 35, 42, 47]
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n = len(arr)
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# Element to be searched
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x = 18
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index = interpolationSearch(arr, 0, n - 1, x)
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if index != -1:
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print("Element found at index", index)
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else:
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print("Element not found")
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