Binary Search Variations

binary-search-variations-1.js

/*
	Given an array of 1's and 0's in the following format:
	[1, 1, 1, 0, 0]
	
	Use binary search to determine how many 1's are in the array.
	You can assume the 1's will always appear together and at the
	beginning of the array.
*/

function bs(array) {
	let left = 0;
	let right = array.length;
	let mid = Math.floor((left + right) / 2);

	while (left < right) {
		mid = Math.floor((left + right) / 2);
		if (array[mid] == 1) {
			left = mid + 1; 
		} else {
			right = mid;
		}
	}
	return left;
}