Sum of Number and Its Reverse — LeetCode 2443 Python Solution

The problem

Given a non-negative integer num, return true if num can be expressed as the sum of any non-negative integer and its reverse, or false otherwise.

Example

Input

num = 443

Output

true

Explanation

172 + 271 = 443 so we return true.

Python solution

class Solution:
    def sumOfNumberAndReverse(self, num: int) -> bool:
        return any(k + int(str(k)[::-1]) == num for k in range(num + 1))

Complexity

Pattern: Math and Number Theory

Find the closed form, the invariant, or the modular identity — and skip the loop entirely. LeetCode 2443. Sum of Number and Its Reverse is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Math.

The math and number theory guide has the Python template for the pattern and the 485 LeetCode problems that use it.

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