Python program to find largest number in a list

• Difficulty Level : Easy
• Last Updated : 05 Mar, 2023

Given a list of numbers, the task is to write a Python program to find the largest number in given list.

Examples:

```Input : list1 = [10, 20, 4]
Output : 20```
```Input : list2 = [20, 10, 20, 4, 100]
Output : 100```

Method 1: Sort the list in ascending order and print the last element in the list.

Python3

 `# Python program to find largest``# number in a list` `# list of numbers``list1 ``=` `[``10``, ``20``, ``4``, ``45``, ``99``]` `# sorting the list``list1.sort()` `# printing the last element``print``(``"Largest element is:"``, list1[``-``1``])`

Output

`Largest element is: 99`

Time Complexity: O(nlogn)
Auxiliary Space: O(1)

Method 2: Using max() method

Python3

 `# Python program to find largest``# number in a list` `# list of numbers``list1 ``=` `[``10``, ``20``, ``4``, ``45``, ``99``]`  `# printing the maximum element``print``(``"Largest element is:"``, ``max``(list1))`

Output

`Largest element is: 99`

Time complexity : O(n)
Auxiliary Space : O(1)

Method 3: Find max list element on inputs provided by user

Python3

 `# Python program to find largest``# number in a list` `# creating empty list``list1 ``=` `[]` `# asking number of elements to put in list``num ``=` `int``(``input``(``"Enter number of elements in list: "``))` `# iterating till num to append elements in list``for` `i ``in` `range``(``1``, num ``+` `1``):``    ``ele ``=` `int``(``input``(``"Enter elements: "``))``    ``list1.append(ele)``    ` `# print maximum element``print``(``"Largest element is:"``, ``max``(list1))`

Output:

```Enter number of elements in list: 4
Enter elements: 12
Enter elements: 19
Enter elements: 1
Enter elements: 99
Largest element is: 99```

Time complexity : O(n)
Auxiliary Space : O(1)

Method 4: Without using built-in functions in python:

Python3

 `# Python program to find largest``# number in a list`  `def` `myMax(list1):` `    ``# Assume first number in list is largest``    ``# initially and assign it to variable "max"``    ``max` `=` `list1[``0``]``# Now traverse through the list and compare``    ``# each number with "max" value. Whichever is``    ``# largest assign that value to "max'.``    ``for` `x ``in` `list1:``        ``if` `x > ``max``:``            ``max` `=` `x` `    ``# after complete traversing the list``    ``# return the "max" value``    ``return` `max`  `# Driver code``list1 ``=` `[``10``, ``20``, ``4``, ``45``, ``99``]``print``(``"Largest element is:"``, myMax(list1))`

Output

`Largest element is: 99`

Time complexity : O(n)
Auxiliary Space : O(1)

Method 5: Use the max() and def functions to find the largest element in a given list. The max() function prints the largest element in the list.

Python3

 `# Python code to find the largest number``# in a list`  `def` `maxelement(lst):``    ``# displaying largest element``    ``# one line solution``    ``print``(``max``(lst))`  `# driver code``# input list``lst ``=` `[``20``, ``10``, ``20``, ``4``, ``100``]``# the above input can also be given as``# lst = list(map(int, input().split()))  # -> taking input from the user``maxelement(lst)`

Output

`100`

Time complexity : O(n)
Auxiliary Space : O(1)

Python3

 `# python code to print largest element in the list` `lst ``=` `[``20``, ``10``, ``20``, ``4``, ``100``]``print``(``max``(lst, key``=``lambda` `value: ``int``(value)) )`

Output

`100`

Time complexity : O(n)
Auxiliary Space : O(n), where n is length of list.

Python3

 `from` `functools ``import` `reduce``lst ``=` `[``20``, ``10``, ``20``, ``4``, ``100``]``largest_elem ``=` `reduce``(``max``, lst)``print``(largest_elem)`

Output

`100`

Time Complexity: O(n)
Auxiliary Space: O(1)

Python3

 `#Function to find the largest element in the list``def` `FindLargest(itr,ele,list1):``  ``if` `itr ``=``=` `len``(list1): ``#Base condition``    ``print``(``"Largest element in the list is: "``, ele)``    ``return``  ``if` `ele < list1[itr]: ``#check max condition``    ``ele ``=` `list1[itr]``  ``FindLargest(itr``+``1``,ele,list1) ``#recursive solution``  ``return``list1``=``[``2``,``1``,``7``,``9``,``5``,``4``]``FindLargest(``0``,list1[``0``],list1)`

Output

`Largest element in the list is:  9`

Time Complexity: O(n)
Auxiliary Space: O(n)

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