2177. Find Three Consecutive Integers That Sum to a Given Number

Description

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 1:

Input: num = 33
Output: [10,11,12]
Explanation: 33 can be expressed as 10 + 11 + 12 = 33.
10, 11, 12 are 3 consecutive integers, so we return [10, 11, 12].

Example 2:

Input: num = 4
Output: []
Explanation: There is no way to express 4 as the sum of 3 consecutive integers.

 

Constraints:

  • 0 <= num <= 1015

Solutions

Solution 1

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

Java Code
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class Solution {
    public long[] sumOfThree(long num) {
        if (num % 3 != 0) {
            return new long[] {};
        }
        long x = num / 3;
        return new long[] {x - 1, x, x + 1};
    }
}

C++ Code
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class Solution {
public:
    vector<long long> sumOfThree(long long num) {
        if (num % 3) {
            return {};
        }
        long long x = num / 3;
        return {x - 1, x, x + 1};
    }
};

Go Code
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func sumOfThree(num int64) []int64 {
	if num%3 != 0 {
		return []int64{}
	}
	x := num / 3
	return []int64{x - 1, x, x + 1}
}

TypeScript Code
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function sumOfThree(num: number): number[] {
    if (num % 3) {
        return [];
    }
    const x = Math.floor(num / 3);
    return [x - 1, x, x + 1];
}