Python – Remove alternate consecutive duplicates
Given list of elements, remove alternate consecutive duplicates of elements.
Input : test_list = [5, 5, 5, 5, 6, 6] Output : [5, 5, 6] Explanation : Alternate occ. of 5 and 6 are removed. Input : test_list = [5, 5, 5, 5] Output : [5, 5] Explanation : Alternate occ. of 5 are removed.
Method : Using loop + remove()
The combination of above functions can be used to solve this problem. In this, we iterate each element and use additional previous element variable to keep track of alternate criteria. The removal is performed using remove().
Python3
# Python3 code to demonstrate working of # Remove alternate consecutive duplicates# Using loop + remove()# initializing liststest_list = [5, 5, 5, 5, 6, 6, 8, 3, 3, 8]# printing original listprint("The original list : " + str(test_list))# Using loop to iterate through elements# element to keep tracktemp = test_list[0]count = 0org_list = test_listidx = 0while(1): # break when idx greater than size if idx >= len(org_list): break # check for alternates if count % 2 and temp == test_list[idx]: test_list.remove(test_list[idx]) idx = idx - 1 count += 1 temp = test_list[idx] else: # keeping track of alternate index increment # and assignment if temp != test_list[idx]: count = 1 temp = test_list[idx] else : count += 1 idx = idx + 1# printing result print("List after alternate duplicates removal : " + str(test_list)) |
Output
The original list : [5, 5, 5, 5, 6, 6, 8, 3, 3, 8] List after alternate duplicates removal : [5, 5, 6, 8, 3, 8]
Time Complexity: O(n), where n is the size of list
Auxiliary Space: O(n), where n is the size of list
