Binary Search

binary-search.js

a = Array.from({length: 15}).map((_,i) => i)

function binarySearch(arr, needle)
{
	let begin = 0, end = arr.length - 1
	while (begin <= end) {
		let mid = Math.floor((end - begin) / 2)  + begin
		if (arr[mid] === needle) {
			return mid
		} else if (arr[mid] > needle) {
			end = mid - 1
		} else {
			begin = mid + 1
		}
	}
	return -1
}

a.forEach((i) => {
	console.log('binarySearch:', binarySearch(a, i))
})
console.log('binarySearch:', binarySearch(a, -1))
console.log('binarySearch:', binarySearch(a, 99))