Python: Create the largest possible number using the elements of a given list of integers

Last update on April 19 2025 13:01:29 (UTC/GMT +8 hours)

Create Largest Number from List

Write a Python program to create the largest possible number using the elements of a given list of positive integers.

Visual Presentation:

Sample Solution:

Python Code:

# Define a function called 'create_largest_number' that constructs the largest possible number from a list of integers.
def create_largest_number(lst):
    # Check if all elements in the list are zero.
    if all(val == 0 for val in lst):
        return '0'  # If all elements are zero, return '0'.

    # Use a sorting approach to create the largest number. Sort in reverse order based on custom comparison criteria.
    result = ''.join(sorted((str(val) for val in lst), reverse=True,
                  key=lambda i: i * (len(str(max(lst))) * 2 // len(i))))
    return result

# Create a list of positive integers 'nums'.
nums = [3, 40, 41, 43, 74, 9]

# Print a message indicating the original list of positive integers.
print("Original list:")
print(nums)

# Print a message indicating the largest possible number that can be created from the elements in 'nums'.
print("Largest possible number using the elements of the said list of positive integers:")
print(create_largest_number(nums))

# Create another list of positive integers 'nums'.
nums = [10, 40, 20, 30, 50, 60]

# Print a message indicating the original list of positive integers.
print("\nOriginal list:")
print(nums)

# Print a message indicating the largest possible number that can be created from the elements in the second 'nums' list.
print("Largest possible number using the elements of the said list of positive integers:")
print(create_largest_number(nums))

# Create a third list of positive integers 'nums'.
nums = [8, 4, 2, 9, 5, 6, 1, 0]

# Print a message indicating the original list of positive integers.
print("\nOriginal list:")
print(nums)

# Print a message indicating the largest possible number that can be created from the elements in the third 'nums' list.
print("Largest possible number using the elements of the said list of positive integers:")
print(create_largest_number(nums)) 

Sample Output:

Original list:
[3, 40, 41, 43, 74, 9]
Largest possible number using the elements of the said list of positive integers:
9744341403

Original list:
[10, 40, 20, 30, 50, 60]
Largest possible number using the elements of the said list of positive integers:
605040302010

Original list:
[8, 4, 2, 9, 5, 6, 1, 0]
Largest possible number using the elements of the said list of positive integers:
98654210

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to arrange a list of non-negative integers to form the largest possible number, handling numbers with similar prefixes correctly.
• Write a Python program to create the largest number from a list after filtering out single-digit numbers.
• Write a Python program to generate the largest possible number by concatenating the string representations of integers in descending order.
• Write a Python program to find the largest number from a list of integers after removing duplicate entries.

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