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58 lines
1.7 KiB
Python
58 lines
1.7 KiB
Python
# Python program for Bitonic Sort. Note that this program
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# works only when size of input is a power of 2.
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# The parameter dir indicates the sorting direction, ASCENDING
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# or DESCENDING; if (a[i] > a[j]) agrees with the direction,
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# then a[i] and a[j] are interchanged.*/
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def compAndSwap(a, i, j, dire):
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if (dire == 1 and a[i] > a[j]) or (dire == 0 and a[i] < a[j]):
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a[i], a[j] = a[j], a[i]
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# It recursively sorts a bitonic sequence in ascending order,
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# if dir = 1, and in descending order otherwise (means dir=0).
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# The sequence to be sorted starts at index position low,
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# the parameter cnt is the number of elements to be sorted.
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def bitonicMerge(a, low, cnt, dire):
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if cnt > 1:
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k = int(cnt / 2)
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for i in range(low, low + k):
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compAndSwap(a, i, i + k, dire)
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bitonicMerge(a, low, k, dire)
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bitonicMerge(a, low + k, k, dire)
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# This function first produces a bitonic sequence by recursively
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# sorting its two halves in opposite sorting orders, and then
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# calls bitonicMerge to make them in the same order
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def bitonicSort(a, low, cnt, dire):
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if cnt > 1:
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k = int(cnt / 2)
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bitonicSort(a, low, k, 1)
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bitonicSort(a, low + k, k, 0)
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bitonicMerge(a, low, cnt, dire)
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# Caller of bitonicSort for sorting the entire array of length N
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# in ASCENDING order
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def sort(a, N, up):
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bitonicSort(a, 0, N, up)
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if __name__ == "__main__":
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# Driver code to test above
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a = []
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n = int(input().strip())
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for i in range(n):
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a.append(int(input().strip()))
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up = 1
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sort(a, n, up)
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print("\n\nSorted array is")
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for i in range(n):
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print("%d" % a[i])
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