Basic Sorting Algorithm: Python implementation

Basic sorting algorithms, including Bubble sorting, insert sorting, select sorting, heap sorting, and quick sorting.

 

[Bubble Sorting]

Complexity is n * n

# Coding: utf8
# Author: HaxtraZ
# Description: Bubble Sorting

Def bubblesort1 ():
# Locate a minimum element each time and place it in the array Header
N = len ()
For I in range (0, n-1 ):
Swapped = False
For j in range (n-1, I,-1 ):
If a [j] <a [J-1]:
A [j], a [J-1] = a [J-1], a [j]
Swapped = True
If not swapped: break

Def bubblesort2 ():
# This version is explained in P137 C ++ 2004
# Locate the largest element and put it at the end of the array each time
# Boundary Optimization
N = len ()
For I in range (0, n-1 ):
Swapped = False
For j in range (0, n-i-1 ):
If a [j]> a [j + 1]:
A [j], a [j + 1] = a [j + 1], a [j]
Swapped = True
If not swapped: break

Def bubblesort3 ():
# This version is from Wikipedia.
# The outer loop is inherently faulty. If it is range (len (a)-,-1)
# When the input data is 3, 5, 1, the result is incorrect.
# Of course, I have modified this error on Wikipedia.
For j in range (len (a)-1, 0,-1 ):
For I in range (0, j ):
If a [I]> a [I + 1]:
A [I], a [I + 1] = a [I + 1], a [I]
　　

Insert sorting]

Complexity is n * n

# Coding: utf8
# Author: HaxtraZ

Def insertion_sort1 ():
# Linear insertion sorting
For j in range (1, len ()):
Key = a [j]
I = j-1
While I> = 0 and a [I]> key:
A [I + 1] = a [I]
I = I-1
A [I + 1] = key

Def binInsertSort ():
# Binary insert sorting
N = len ()
For j in range (1, n ):
Key = a [j]
I = j-1

If key> a [I]:
Continue
L, r = 0, I
While l <= r:
# Print l, r
Mid = (l + r)/2
If key <a [mid]:
R = mid-1
Else:
L = mid + 1
K = j
While k> l:
A [k] = a [k-1]
K = k-1

A [l] = key
　　

[Select sorting]

Complexity is n * n

# Coding: utf8
# Author: HaxtraZ
# Description: Select sorting

Def selectsort1 ():
# Finding the minimum element each time
N = len ()
For I in range (0, n-1 ):
For j in range (I + 1, n ):
Minpos = I # subscripts used to record the smallest element
If a [j] <a [minpos]:
Minpos = j
# If a [j] And a [minpos] are exchanged here, the bubblesort

If minpos! = I:
A [minpos], a [I] = a [I], a [minpos]

Def selectsort2 ():
# Find the largest element each time
N = len (n)
For I in range (n-1, 0,-1 ):
Maxpos = 0
For j in range (1, I + 1 ):
If a [j]> a [maxpos]:
Maxpos = j

If maxpos! = I:
A [I], a [maxpos] = a [maxpos], a [I]
　　

[Heap sorting]

Complexity is nlogn

# Coding: utf8
# Author: HaxtraZ
# Description: heap sorting
# Modified from introduction to algorithms 2nd Edition

Def LEFT (I ):
Return 2 * I + 1

Def RIGHT (I ):
Return 2 * I + 2

Def PARENT (I ):
Return (I-1)/2

Def MAX_HEAPIFY (a, I, heapsize ):
L = LEFT (I)
R = RIGHT (I)
If l Largest = l
Else:
Largest = I

If r Largest = r

If largest! = I:
A [I], a [largest] = a [largest], a [I]
MAX_HEAPIFY (a, largest, heapsize)

Def BUILD_MAX_HEAP ():
Heapsize = len ()
I = PARENT (len (a)-1)
While I> = 0:
MAX_HEAPIFY (a, I, heapsize)
I-= 1

Def HEAP_SORT ():
BUILD_MAX_HEAP ()
N = len ()
Heapsize = n
For I in range (n-1, 0,-1 ):
A [0], a [I] = a [I], a [0]
Heapsize-= 1
MAX_HEAPIFY (a, 0, heapsize)

A = [,]
HEAP_SORT ()
Print
　　

[Quick sorting]

Complexity is nlogn

# Coding: utf8
# Version1
 
Def quickSort (alist ):
QuickSortHelper (alist, 0, len (alist)-1)

Def quickSortHelper (alist, first, last ):
If first <last:

Splitpoint = partition (alist, first, last)

QuickSortHelper (alist, first, splitpoint-1)
QuickSortHelper (alist, splitpoint + 1, last)

Def partition (alist, first, last ):
Required tvalue = alist [first]

Leftmark = first + 1
Rightmark = last

Done = False
While not done:

While leftmark <= rightmark and \
Alist [leftmark] <= effectvalue:
Leftmark = leftmark + 1

While alist [rightmark]> = effectvalue and \
Rightmark> = leftmark:
Rightmark = rightmark-1

If rightmark <leftmark:
Done = True
Else:
Temp = alist [leftmark]
Alist [leftmark] = alist [rightmark]
Alist [rightmark] = temp

Temp = alist [first]
Alist [first] = alist [rightmark]
Alist [rightmark] = temp

Return rightmark

Alist = [54,26, 93,17, 77,31, 44,55, 20]
QuickSort (alist)
Print (alist)