Python: Create all possible permutations from a given collection of distinct numbers

Last update on April 17 2025 13:01:46 (UTC/GMT +8 hours)

List Permutations Generator

Write a Python program that generates a list of all possible permutations from a given collection of distinct numbers.

Visual Presentation:

Python: Create all possible permutations from a given collection of distinct numbers

Sample Solution:

Python Code:

# Define a function 'permute' that generates all permutations of a list of numbers.
def permute(nums):
    # Initialize the result list with an empty permutation.
    result_perms = [[]]

    # Iterate through each number in the input list.
    for n in nums:
        # Create a new list to store permutations with the current number.
        new_perms = []

        # Iterate through each existing permutation in the result list.
        for perm in result_perms:
            # Insert the current number at different positions within each existing permutation.
            for i in range(len(perm)+1):
                new_perms.append(perm[:i] + [n] + perm[i:])

        # Update the result list with the new permutations.
        result_perms = new_perms

    # Return the final list of permutations.
    return result_perms

# Create a list of numbers.
my_nums = [1, 2, 3]

# Print the original collection and the collection of distinct numbers.
print("Original Collection: ", my_nums)
print("Collection of distinct numbers:\n", permute(my_nums))

Sample Output:

Original Cofllection:  [1, 2, 3]
Collection of distinct numbers:
 [[3, 2, 1], [2, 3, 1], [2, 1, 3], [3, 1, 2], [1, 3, 2], [1, 2, 3]]

Explanation:

This above Python code defines a function called "permute()" that generates all permutations of a list of numbers. Here's a brief explanation:

The function "permute()" takes a list of numbers ('nums') as input.
It initializes a list 'result_perms' with an empty permutation to store the final results.
It iterates through each number in the input list.
For each number, it creates a new list ('new_perms') to store permutations with the current number.
It iterates through each existing permutation in the result list.
For each existing permutation, it inserts the current number at different positions to create new permutations.
It updates the 'result_perms' list with the new permutations.
The function returns the final list of permutations.

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to generate all permutations of a list of numbers where repetition is allowed.
Write a Python program to generate all permutations of the characters in a given string.
Write a Python program to generate all partial permutations (of length k) from a list of distinct numbers.
Write a Python program to compute the next lexicographic permutation for a given list of numbers.

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