📜  用于计数排序的Python程序

📅  最后修改于: 2022-05-13 01:56:56.602000             🧑  作者: Mango

用于计数排序的Python程序

计数排序是一种基于特定范围之间的键的排序技术。它通过计算具有不同键值(散列类型)的对象的数量来工作。然后做一些算术来计算每个对象在输出序列中的位置。

Python3
# Python program for counting sort
 
# The main function that sort the given string arr[] in
# alphabetical order
def countSort(arr):
 
    # The output character array that will have sorted arr
    output = [0 for i in range(256)]
 
    # Create a count array to store count of individual
    # characters and initialize count array as 0
    count = [0 for i in range(256)]
 
    # For storing the resulting answer since the
    # string is immutable
    ans = ["" for _ in arr]
 
    # Store count of each character
    for i in arr:
        count[ord(i)] += 1
 
    # Change count[i] so that count[i] now contains actual
    # position of this character in output array
    for i in range(256):
        count[i] += count[i-1]
 
    # Build the output character array
    for i in range(len(arr)):
        output[count[ord(arr[i])]-1] = arr[i]
        count[ord(arr[i])] -= 1
 
    # Copy the output array to arr, so that arr now
    # contains sorted characters
    for i in range(len(arr)):
        ans[i] = output[i]
    return ans
 
# Driver program to test above function
arr = "geeksforgeeks"
ans = countSort(arr)
print ("Sorted character array is %s"  %("".join(ans)))
 
# This code is contributed by Nikhil Kumar Singh


输出:

Sorted character array is eeeefggkkorss

请参阅有关计数排序的完整文章以获取更多详细信息!