Question

def selectionSortK(alist, k):
for i in range(0,len(alist) - 1):
min = i
for j in range(i + 1, len(alist)):
if alist[j] < alist[min]:
min = j
temp = alist[i]
alist[i] = alist[min]
alist[min] = temp

P3: Sanity Test: Is selectionSortK callable? ... ok
test_doNothing (__main__.TestProblem3)
P3: Does sorting the first k elements with k=0 do nothing? ... ok
test_onePass (__main__.TestProblem3)
P3: Sorting a portion of a decreasing list ... FAIL
test_severalPasses (__main__.TestProblem3)
P3: Sorting a decreasing list in several stages ... FAIL

Problem 3 Selection sort (15 points) To gain familiarity with selection sort, add an extra parameter k to the selection sort procedure presented in class in Lecture 19 slide 45. Modify the loop so that selection sort runs in linear time for fixed k by retuming early with only the first k items in the list sorted. ergesort Here's how these functions would sort a list of integers: [7 2 8 5 1 3 6 4] mergesort [7 2 8 5] [1 3 6 4] mergesort 17 2] [8 5] [1 3] [6 4] mergesort 7 2

Answer 1

Please find the program to sort a list of first k items and return only the first k sorted items.

Note: I have ignored merge sort because there is not questions asked about it here...

Program:

def selectionSortK(alist, k):
if k == 0:
print("K is 0, no alteration in the list")
return
  
if k > len(alist):
print("K is greater than the length of list, no alteration in list")
return
  
#traverse the list based on k
for i in range(0,k - 1):
min = i
#compare the list elements with k range not with len of list
for j in range(i + 1, k):
if alist[j] < alist[min]:
min = j
temp = alist[i]
alist[i] = alist[min]
alist[min] = temp
  

#delete the remainng elements in a list based on k
if k < len(alist):
for i in range(k-1, len(alist)-1):
del alist[k]
  
lsit=[7, 2, 8, 5, 1, 3, 6, 4]
print("Input list is ")
print(lsit)
selectionSortK(lsit, 3)

print("Sorted list is ")
print(lsit)

Output:

Input list is
[7, 2, 8, 5, 1, 3, 6, 4]
Sorted list is
[2, 7, 8]

Screen shot:

1 def selectionSortK (alist, k): print("K is 0, no alteration in the list" 4 return if k len(alist): print ("K is greater than the length of list, no alteration in list") return #traverse the List based on k 10 for i in range (e,k - 1): forinarecane 12 #compare the list elements with k range not with Len of list for j in range(i +1, k): if alist[] alist[ r]: 13 14- 15 16 17 temp alist[i] alist[i] alist[min] alist[min] temp #delete the remainng elements in a list based on k if k < le (alist): for i in range(k-1, len(alist)-1): del alist[k] 18 19 20 21- 23 24 25 lsit-[7, 2, 8, 5, 1, 3, 6, 4] 26 print ("Input list is ") 27 print (lsit) 28 selectionSortK(1sit, 3) 29 print("Sorted list is") 30 print (lsit)