Given a list of list, the task is to find sublist with the maximum value in second column.
Examples:
Input : [['Paras', 90], ['Jain', 32], ['Geeks', 120],
['for', 338], ['Labs', 532]]
Output :['Labs', 532]
Input: [['Geek', 90], ['For', 32], ['Geeks', 120]]
Output: ['Geeks', 120]
Below are some tasks to achieve the above task.
Method #1: Using lambda
Python3
# Python code to find maximum value# in second column of list of list# Input list initializationInput = [['Paras', 90], ['Jain', 32], ['Geeks', 120], ['for', 338], ['Labs', 532]]# Using lambdaOutput = max(Input, key=lambda x: x[1])# printing outputprint("Input List is :", Input)print("Output list is : ", Output) |
Input List is : [[‘Paras’, 90], [‘Jain’, 32], [‘Geeks’, 120], [‘for’, 338], [‘Labs’, 532]] Output list is : [‘Labs’, 532]
Time Complexity: O(n log n) – where n is the number of elements in the input list, as the max function applies the key function to each element of the input list and then performs a comparison between elements to determine the maximum
Auxiliary Space Complexity: O(1)
Method #2: Using itemgetter
Python3
# Python code to find maximum value# in second column of list of list# Importingimport operator# Input list initializationInput = [['Paras', 90], ['Jain', 32], ['Geeks', 120], ['for', 338], ['Labs', 532]]# Using itemgetterOutput = max(Input, key=operator.itemgetter(1))# Printing outputprint("Input List is :", Input)print("Output list is : ", Output) |
Input List is : [[‘Paras’, 90], [‘Jain’, 32], [‘Geeks’, 120], [‘for’, 338], [‘Labs’, 532]] Output list is : [‘Labs’, 532]
Time Complexity: O(n log n) where n is the number of elements in the Input list. This is because the max() function sorts the list of lists to find the maximum value. The sorting operation takes O(n log n) time.
Auxiliary Space: O(1), because we’re only storing the result of the max() function, which has a constant size of 1.
Method #3 : Using max() and for loop
Python3
# Python code to find maximum value# in second column of list of list# Input list initializationInput = [['Paras', 90], ['Jain', 32], ['Geeks', 120], ['for', 338], ['Labs', 532]]x=[]for i in Input: x.append(i[1])ma=max(x)for i in Input: if ma in i: Output=i break# printing outputprint("Input List is :", Input)print("Output list is : ", Output) |
Input List is : [['Paras', 90], ['Jain', 32], ['Geeks', 120], ['for', 338], ['Labs', 532]] Output list is : ['Labs', 532]
Time Complexity: O(n*n), where n is the length of the list test_dict
Auxiliary Space: O(n) additional space of size n is created where n is the number of elements in the res list
Method #4 : Using reduce
To find the sublist with the maximum value in the second column of a given nested list using the reduce function from the functools module, you can use the following approach:
Python3
from functools import reduce# Input list initializationinput_list = [['Paras', 90], ['Jain', 32], ['Geeks', 120], ['for', 338], ['Labs', 532]]# Using reduceoutput = reduce(lambda x, y: x if x[1] > y[1] else y, input_list)# Printing outputprint("Input List is :", input_list)print("Output list is : ", output)#This code is contributed by Edula Vinay Kumar Reddy |
Input List is : [['Paras', 90], ['Jain', 32], ['Geeks', 120], ['for', 338], ['Labs', 532]] Output list is : ['Labs', 532]
This will output [‘Labs’, 532], which is the sublist with the maximum value in the second column.
Note: The reduce function applies a function to each element of the list in a cumulative manner, starting from the first element and moving to the last element. In this case, the function compares the second element of each sublist (the value in the second column) and returns the sublist with the maximum value.
Time complexity: O(n)
Auxiliary space: O(1)
Method 5: using the built-in function sorted() with a custom sorting key.
Python3
Input = [['Paras', 90], ['Jain', 32], ['Geeks', 120], ['for', 338], ['Labs', 532]]# Sort the input list in descending order based on the second element of each sublistsorted_list = sorted(Input, key=lambda x: x[1], reverse=True)# The first element of the sorted list will be the sublist with the maximum second elementmax_value_sublist = sorted_list[0]print("Input List is :", Input)print("Max value sublist is : ", max_value_sublist) |
Input List is : [['Paras', 90], ['Jain', 32], ['Geeks', 120], ['for', 338], ['Labs', 532]] Max value sublist is : ['Labs', 532]
Time complexity: O(n log n), where n is the length of the input list.
Auxiliary space: O(n) to store the sorted list.
