Python/project_euler/problem_119/sol1.py
Ravi Kandasamy Sundaram 2b5b2c6304
Added solution for Project Euler problem 119 (#2931)
Name: Digit power sum

Problem Statement: The number 512 is interesting because it is equal to the sum of its digits raised to some power: 5 + 1 + 2 = 8, and 83 = 512. Another example of a number with this property is 614656 = 284.
We shall define an to be the nth term of this sequence and insist that a number must contain at least two digits to have a sum.
You are given that a2 = 512 and a10 = 614656.
Find a30

Reference: https://projecteuler.net/problem=119

reference: #2695

Co-authored-by: Ravi Kandasamy Sundaram <rkandasamysundaram@luxoft.com>
2020-10-10 23:29:02 +05:30

52 lines
1.2 KiB
Python

"""
Problem 119: https://projecteuler.net/problem=119
Name: Digit power sum
The number 512 is interesting because it is equal to the sum of its digits
raised to some power: 5 + 1 + 2 = 8, and 8^3 = 512. Another example of a number
with this property is 614656 = 28^4. We shall define an to be the nth term of
this sequence and insist that a number must contain at least two digits to have a sum.
You are given that a2 = 512 and a10 = 614656. Find a30
"""
import math
def digit_sum(n: int) -> int:
"""
Returns the sum of the digits of the number.
>>> digit_sum(123)
6
>>> digit_sum(456)
15
>>> digit_sum(78910)
25
"""
return sum([int(digit) for digit in str(n)])
def solution(n: int = 30) -> int:
"""
Returns the value of 30th digit power sum.
>>> solution(2)
512
>>> solution(5)
5832
>>> solution(10)
614656
"""
digit_to_powers = []
for digit in range(2, 100):
for power in range(2, 100):
number = int(math.pow(digit, power))
if digit == digit_sum(number):
digit_to_powers.append(number)
digit_to_powers.sort()
return digit_to_powers[n - 1]
if __name__ == "__main__":
print(solution())