Python – Rearrange elements second index greater than first
Given 2 lists, for a given index, 2nd list element is always larger than first, and if not, we rearrange it.
Input : test_list1 = [36, 38, 40, 132], test_list2 = [35, 37, 39, 41, 133]
Output : [37, 39, 41, 133]
Explanation : Each element in result list is greater than its index counterpart of 1st list. (Eg. 37 > 36)Input : test_list1 = [2, 6], test_list2 = [5, 3, 8]
Output : [5, 8]
Explanation : Here 5 > 2 and 8 > 6.
Method 1: Using loop This is brute way to tackle this problem. In this, we try to get best suitable next higher element after the whole list traversal and perform the necessary rearrangement.
Python3
# Python3 code to demonstrate working of # Rearrange elements second index greater than first# Using loop# initializing liststest_list1 = [14, 16, 18, 110]test_list2 = [13, 15, 17, 19, 111]# printing original listsprint("The original list 1 is : " + str(test_list1))print("The original list 2 is : " + str(test_list2))# Rearrange elements second index greater than first# Using loopx = y = 0res1, res2 = [], []while x < len(test_list2) and y < len(test_list1): # checking for greater element if test_list2[x] > test_list1[y]: res2.append(test_list2[x]) res1.append(test_list1[y]) while y < len(test_list1) and test_list2[x] > test_list1[y]: res1[-1] = test_list1[y] y += 1 x += 1# printing result print("List 2 after conversion : " + str(res2)) |
The original list 1 is : [14, 16, 18, 110] The original list 2 is : [13, 15, 17, 19, 111] List 2 after conversion : [15, 17, 19, 111]
Time complexity: O(n), where n is the length of test_list1 + test_list2.
Auxiliary Space: O(n), where n is the length of test_list1 + test_list2. The additional space is used to store the rearranged lists res1 and res2.
Method 2: Using list comprehension
Python3
# Python3 code to demonstrate working of# Rearrange elements second index greater than first# Using list comprehensions# initializing liststest_list1 = [14, 16, 18, 110]test_list2 = [13, 15, 17, 19, 111]# printing original listsprint("The original list 1 is : " + str(test_list1))print("The original list 2 is : " + str(test_list2))# Rearranging elements in list 2 such that the second index is greater than the firstx = 0res2 = [test_list2[i] for i in range(len(test_list2)) if x < len(test_list1) and test_list2[i] > test_list1[x]]x = [i for i in range(len(test_list1)) if x < len(test_list2) and test_list2[x] > test_list1[i]]# printing resultprint("List 2 after conversion : " + str(res2))#This code is contributed by Vinay pinjala. |
The original list 1 is : [14, 16, 18, 110] The original list 2 is : [13, 15, 17, 19, 111] List 2 after conversion : [15, 17, 19, 111]
Time complexity: O(n)
Auxiliary Space: O(n)
