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Create BitonicSort.py (TheAlgorithms#386)
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# Python program for Bitonic Sort. Note that this program | ||
# works only when size of input is a power of 2. | ||
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# The parameter dir indicates the sorting direction, ASCENDING | ||
# or DESCENDING; if (a[i] > a[j]) agrees with the direction, | ||
# then a[i] and a[j] are interchanged.*/ | ||
def compAndSwap(a, i, j, dire): | ||
if (dire == 1 and a[i] > a[j]) or (dire == 0 and a[i] < a[j]): | ||
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). | ||
# The sequence to be sorted starts at index position low, | ||
# the parameter cnt is the number of elements to be sorted. | ||
def bitonicMerge(a, low, cnt, dire): | ||
if cnt > 1: | ||
k = int(cnt / 2) | ||
for i in range(low, low + k): | ||
compAndSwap(a, i, i + k, dire) | ||
bitonicMerge(a, low, k, dire) | ||
bitonicMerge(a, low + k, k, dire) | ||
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# This funcion first produces a bitonic sequence by recursively | ||
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# sorting its two halves in opposite sorting orders, and then | ||
# calls bitonicMerge to make them in the same order | ||
def bitonicSort(a, low, cnt, dire): | ||
if cnt > 1: | ||
k = int(cnt / 2) | ||
bitonicSort(a, low, k, 1) | ||
bitonicSort(a, low + k, k, 0) | ||
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 | ||
def sort(a, N, up): | ||
bitonicSort(a, 0, N, up) | ||
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# Driver code to test above | ||
a = [] | ||
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n = int(input()) | ||
for i in range(n): | ||
a.append(int(input())) | ||
up = 1 | ||
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sort(a, n, up) | ||
print("\n\nSorted array is") | ||
for i in range(n): | ||
print("%d" % a[i]) |