Algorithm: Bubble sort (python version)

1. After sorting n elements from large to small, select the K-Large element

#!/usr/bin/env python#Coding-*-Utf:8-*-#bubble Sort Select K elementImportRandomImport TimedefSelect_k (): N= Int (Input ("The length of the array to be generated:")) Arraya= []     forIinchrange (N): x= Random.choice (Range (100)) arraya.append (x)Print("the resulting array (not sorted):", Arraya) Arrayb=Bubble_sort (Arraya)Print("sorted Array:", Arrayb) k= Int (Input ("Select the first few elements:"))    #from large to small k elementsresult = Arrayb[k-1]    returnresultdefBubble_sort (a): forIinchRange (len (a)): forJinchRange (I,len (a)):ifa[i]<A[j]: tmp=A[i] A[i]=A[j] A[j]=tmpreturnaif __name__=='__main__': T0=Time.clock ()Print("The first k elements are:", Select_k ())#the second call to clock () minus the first call to clock () is the time that the program executes    Print("Time of program execution:", Time.clock ()-t0)

2. bubble sort before K elements, the following elements are compared with the K element, if less than ignore, if greater than add to the correct position and remove the last element

#!/usr/bin/env python#Coding-*-Utf:8-*-#bubble Sort before the k elements, followed by the elements are compared to the K-element, if less than ignored, if greater than#add to the correct position and remove the last elementImportRandomImport TimedefSelect_k (): N= Int (Input ("The length of the array to be generated:")) K= Int (Input ("Select the first few elements:")) Arraya= []     forIinchrange (N): x= Random.choice (Range (100)) arraya.append (x)Print("the resulting array (not sorted):", Arraya) Arrayb=Bubble_sort (arraya[:k])Print("array of first k elements sorted:", Arrayb) forIinchRange (k, n):if(arrayb[-1]<Arraya[i]): Arrayb.append (Arraya[i]) Arrayb=Bubble_sort (Arrayb) arrayb.pop ()#returns the first K-Large elementresult = Arrayb[-1]    returnresultdefBubble_sort (a): forIinchRange (len (a)): forJinchRange (I,len (a)):ifa[i]<A[j]: tmp=A[i] A[i]=A[j] A[j]=tmpreturnaif __name__=='__main__': T0=Time.clock ()Print("the K-large elements are:", Select_k ())#the second call to clock () minus the first call to clock () is the time that the program executes    Print("Time of program execution:", Time.clock ()-t0)

3. Time Comparison

Method One:

N |  10 |  100 |   1000 |   5000 | 10000 | 20000 |

T |  0.0 |  0.001 |   0.06 |   1.17 |  4.65 | 18.25 |

Method Two:

N |  10 |  100 |   1000 |   5000 | 10000 | 20000 |

T |   0.0 |   0.0 |   0.0 |   0.02 |  0.02 | 0.03 |

Algorithm: Bubble sort (python version)