(binary search trees) which form the basis of modern databases and immutable data structures. Binary search works very much the way humans intuitively search for a name in a yellow pages directory (if you have ever seen one) or the dictionary.
In this lesson we learn how to implement a Binary Search Algorithm using TypeScript / Javascript, and we describe the problem that it solves.
function binarySearch( array: number[], element: number, start: number = 0, end: number= array.length -1 ): number { if(end < start) { return -1; } const middle = Math.floor((start + end) / 2); return element === array[middle] ? middle : element < array[middle] ? binarySearch(array, element, start, middle - 1) : binarySearch(array, element, middle + 1, end); } const unsortedArray = [ 6, 7, 8, 9, 10, 1, 2, 3, 4, 5] console.log("Index of 4: ", binarySearch(unsortedArray.sort(), 4)) console.log("22 not found: ", binarySearch(unsortedArray.sort(), 22))
[Algorithms] Binary Search Algorithm using TypeScript
原文：http://www.cnblogs.com/Answer1215/p/7219523.html