Find Three Largest Number

Write a function that takes in an array of at least three integers and, without sorting the input array, returns a sorted array of the three largest integers in the input array.

The function should return duplicate integers if necessary; for example, it should return [10, 10, 12] for an input array of [10, 5, 9, 10, 12].

Sample Input

array = [141, 1, 17, -7, -17, -27, 18, 541, 8, 7, 7]

array = [141, 1, 17, -7, -17, -27, 18, 541, 8, 7, 7]

Sample Output

[18, 141, 541]

[18, 141, 541]

Hints

Hint 1

Can you keep track of the three largest numbers in an array as you traverse the input array?

Hint 2

Following the suggestion in Hint #1, try traversing the input array and updating the three largest numbers if necessary by shifting them accordingly.

Optimal Space & Time Complexity

O(n) time | O(1) space - where n is the length of the input array

function findThreeLargestNumbers(array) {
  if (array.length < 3) return;
	let arr = []
	
	for (let i = 0; i < 3; i++) {
		let maximum = Math.max(...array)
		let index = array.indexOf(maximum)
		let temp = array.splice(index, 1)[0]
		arr.push(temp)
	}
	return arr.sort((a, b) => a - b)
}

function findThreeLargestNumbers(array) {
  if (array.length < 3) return;
	let arr = []
	
	for (let i = 0; i < 3; i++) {
		let maximum = Math.max(...array)
		let index = array.indexOf(maximum)
		let temp = array.splice(index, 1)[0]
		arr.push(temp)
	}
	return arr.sort((a, b) => a - b)
}

🐁