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42 lines
1.2 KiB
Python
42 lines
1.2 KiB
Python
# Python program for counting sort
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# This is the main function that sort the given string arr[] in
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# in the alphabetical order
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def countSort(arr):
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# The output character array that will have sorted arr
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output = [0 for i in range(256)]
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# Create a count array to store count of inidividul
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# characters and initialize count array as 0
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count = [0 for i in range(256)]
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# For storing the resulting answer since the
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# string is immutable
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ans = ["" for _ in arr]
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# Store count of each character
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for i in arr:
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count[ord(i)] += 1
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# Change count[i] so that count[i] now contains actual
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# position of this character in output array
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for i in range(256):
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count[i] += count[i-1]
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# Build the output character array
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for i in range(len(arr)):
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output[count[ord(arr[i])]-1] = arr[i]
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count[ord(arr[i])] -= 1
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# Copy the output array to arr, so that arr now
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# contains sorted characters
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for i in range(len(arr)):
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ans[i] = output[i]
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return ans
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# Driver program to test above function
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arr = "thisisthestring"
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ans = countSort(arr)
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print ("Sorted string array is %s" %("".join(ans)))
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