Find Three Consecutive Integers That Sum to a Given Number — LeetCode 2177 Python Solution

The problem

Given an integer num, return three consecutive integers (as a sorted array) that sum to num. If num cannot be expressed as the sum of three consecutive integers, return an empty array.

Example

Input

num = 33

Output

[10,11,12]

Explanation

33 can be expressed as 10 + 11 + 12 = 33.

Python solution

class Solution:
    def sumOfThree(self, num: int) -> List[int]:
        x, mod = divmod(num, 3)
        return [] if mod else [x - 1, x, x + 1]

Complexity

Pattern: Math and Number Theory

Find the closed form, the invariant, or the modular identity — and skip the loop entirely. LeetCode 2177. Find Three Consecutive Integers That Sum to a Given Number 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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