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

Problem 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.

Examples

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 <= 10^15

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

1. Function Definition:

   • Define a function sumOfThree that takes a number num as input.
   • Initialize an empty list v to store the result.

2. Check Divisibility:

   • Check if num is divisible by 3.
   • If not, return the empty list v.

3. Calculate Consecutive Integers:

   • If num is divisible by 3, calculate the three consecutive integers:
     • The first integer is (num / 3) - 1.
     • The second integer is num / 3.
     • The third integer is (num / 3) + 1.
   • Add these integers to the list v.

4. Return the Result:

   • Return the list v containing the three consecutive integers if they exist, otherwise return the empty list.

Solution

Implementation

Live Editor

  function  sumOfThree(num) {
    let v = [];
    if (num % 3 === 0) {
        v.push((num / 3) - 1);
        v.push(num / 3);
        v.push((num / 3) + 1);
    }
    return v;
}
  const input  = 33
  const output = sumOfThree(input)
  return (
    <div>
      <p>
        <b>Input: </b>
        {JSON.stringify(input)}
      </p>
      <p>
        <b>Output:</b> {output.toString()}
      </p>
    </div>
  );
}

Result

Loading...

Complexity Analysis

• Time Complexity: $O(1)$
• Space Complexity: $O(1)$

Code in Different Languages

JavaScript

Written by @hiteshgahanolia

class Solution {
 sumOfThree(num) {
     let v = [];
     if (num % 3 === 0) {
         v.push((num / 3) - 1);
         v.push(num / 3);
         v.push((num / 3) + 1);
     }
     return v;
 }
}

TypeScript

Written by @hiteshgahanolia

class Solution {
 sumOfThree(num: number): number[] {
     let v: number[] = [];
     if (num % 3 === 0) {
         v.push((num / 3) - 1);
         v.push(num / 3);
         v.push((num / 3) + 1);
     }
     return v;
 }
}

Python

Written by @hiteshgahanolia

class Solution:
 def sumOfThree(self, num: int):
     v = []
     if num % 3 == 0:
         v.append((num // 3) - 1)
         v.append(num // 3)
         v.append((num // 3) + 1)
     return v

Java

Written by @hiteshgahanolia

import java.util.*;

class Solution {
 public List<Long> sumOfThree(long num) {
     List<Long> v = new ArrayList<>();
     if (num % 3 == 0) {
         v.add((num / 3) - 1);
         v.add(num / 3);
         v.add((num / 3) + 1);
     }
     return v;
 }
}

C++

Written by @hiteshgahanolia

class Solution {
public:
 vector<long long> sumOfThree(long long num) {
     vector<long long>v;
     if(num%3==0)
     {
         v.push_back((num/3)-1);
         v.push_back((num/3));
         v.push_back((num/3)+1);
     }
     else
     {
         return v;
     }
     return v;
     
 }
};

References

• LeetCode Problem: 2177. Find Three Consecutive Integers That Sum to a Given Number

• Solution Link: LeetCode Solution