Python: Next bigger number by rearranging the digits of a given number

Last update on December 21 2024 07:31:20 (UTC/GMT +8 hours)

Write a Python program to create the next bigger number by rearranging the digits of a given number.

Sample Solution:

Python Code :

# Define a function 'rearrange_bigger' that takes an integer 'n' as input
def rearrange_bigger(n):
    # Convert the number 'n' into a list of its digits represented as strings
    nums = list(str(n))
    
    # Iterate through the digits from the second-to-last to the first digit
    for i in range(len(nums) - 2, -1, -1):
        # Check if the current digit is less than the next digit
        if nums[i] < nums[i + 1]:
            # Slice the list from the current index to the end and store it in 'z'
            z = nums[i:]
            
            # Find the smallest digit greater than the current digit
            y = min(filter(lambda x: x > z[0], z))
            
            # Remove 'y' from the list 'z'
            z.remove(y)
            
            # Sort the remaining elements in 'z'
            z.sort()
            
            # Rearrange the digits in 'nums' to form the next bigger number
            nums[i:] = [y] + z
            
            # Convert the rearranged list of digits back into an integer and return it
            return int("".join(nums))
    
    # If no bigger number can be formed, return False
    return False

# Test cases to demonstrate the function's behavior with different input numbers

n = 12
print("Original number:", n)
print("Next bigger number:", rearrange_bigger(n))

n = 10
print("\nOriginal number:", n)
print("Next bigger number:", rearrange_bigger(n))

n = 201
print("\nOriginal number:", n)
print("Next bigger number:", rearrange_bigger(n))

n = 102
print("\nOriginal number:", n)
print("Next bigger number:", rearrange_bigger(n))

n = 445
print("\nOriginal number:", n)
print("Next bigger number:", rearrange_bigger(n)) 

Sample Output:

Original number: 12
Next bigger number: 21

Original number: 10
Next bigger number: False

Original number: 201
Next bigger number: 210

Original number: 102
Next bigger number: 120

Original number: 445
Next bigger number: 454

Python Code Editor:

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