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Python实现桶排序与快速排序算法结合应用示例

更新时间:2020-05-11 19:06:01 作者:startmvc
本文实例讲述了Python实现桶排序与快速排序算法结合应用的方法。分享给大家供大家参考,

本文实例讲述了Python实现桶排序与快速排序算法结合应用的方法。分享给大家供大家参考,具体如下:


#-*- coding: UTF-8 -*-
import numpy as np
from QuickSort import QuickSort
def BucketSort(a, n):
 barrel = {}
 for i in xrange(0,n):
 barrel.setdefault(i, [])
 min = np.min(a)
 max = np.max(a)
 for x in a:
 for i in xrange(0,n-1):
 if x >= min +i* (max - min)/n and x < min +(i +1) * (max - min)/n:
 barrel[i].append(x)
 elif i == n-2 and x >= min +(i +1) * (max - min)/n:
 barrel[i+1].append(x)
 k = 0
 for i in xrange(0,n):
 if len(barrel[i]) != 0:
 arr = np.array(barrel[i])
 QuickSort(arr, 0, len(barrel[i]) -1)
 for x in arr:
 a[k] = x
 k += 1
if __name__ == '__main__':
 a = np.random.randint(0, 100, size = 10)
 print "Before sorting..."
 print "---------------------------------------------------------------"
 print a
 print "---------------------------------------------------------------"
 BucketSort(a, 10)
 print "After sorting..."
 print "---------------------------------------------------------------"
 print a
 print "---------------------------------------------------------------"

快速排序QuickSort:


#-*- coding: UTF-8 -*-
import numpy as np
def Partition(a, i, j):
 x = a[i] #将数组的第一个元素作为初始基准位置
 p = i #同时记录下该元素的位置
 while i < j:
 while i < j and a[j] >= x:
 j -= 1
 while i < j and a[i] <= x:
 i += 1
 if i != j:
 a[i], a[j] = a[j], a[i] #交换a[i]与a[j]
 a[p], a[i] = a[i], a[p] #将a[p]与a[i]进行交换
 p = i #得到分隔位置
 return p
def QuickSort(a, i, j):
 if i < j:
 p = Partition(a, i, j)
 QuickSort(a, i, p-1)
 QuickSort (a, p+1, j)
if __name__ == '__main__':
 a = np.random.randint(0, 100, size = 100)
 print "Before sorting..."
 print "---------------------------------------------------------------"
 print a
 print "---------------------------------------------------------------"
 QuickSort(a, 0, a.size - 1)
 print "After sorting..."
 print "---------------------------------------------------------------"
 print a
 print "---------------------------------------------------------------"

程序运行结果:

Python 桶排序 快速排序 算法