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

Python Lambda: Exercise-25 with Solution

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

Sample Solution:

Python Code :

def rearrange_bigger(n):
    #Break the number into digits and store in a list
    nums = list(str(n))
    for i in range(len(nums)-2,-1,-1):
        if nums[i] < nums[i+1]:
            z = nums[i:]
            y = min(filter(lambda x: x > z[0], z))
            z.remove(y)
            z.sort()
            nums[i:] = [y] + z
            return int("".join(nums))
    return False
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

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Previous: Write a Python program to find numbers within a given range where every number is divisible by every digit it contains.
Next: Write a Python program to find the list with maximum and minimum length using lambda.

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Python: Tips of the Day

Python: Cache results with decorators

There is a great way to cache functions with decorators in Python. Caching will help save time and precious resources when there is an expensive function at hand.

Implementation is easy, just import lru_cache from functools library and decorate your function using @lru_cache.

from functools import lru_cache

@lru_cache(maxsize=None)
def fibo(a):
    if a <= 1:
        return a
    else:
        return fibo(a-1) + fibo(a-2)

for i in range(20):
    print(fibo(i), end="|")

print("\n\n", fibo.cache_info())

Output:

0|1|1|2|3|5|8|13|21|34|55|89|144|233|377|610|987|1597|2584|4181|

 CacheInfo(hits=36, misses=20, maxsize=None, currsize=20)