Nodejs Array Search Binary bsearch(target)

Method Source Code

Array.prototype.bsearch = function (target) {
  var half = parseInt(this.length / 2);
  if (target === this[half]) {
    return half;// www. ja  va  2 s  .  c o  m
  }
  if (target > this[half]) {
    return half + this.slice(half,this.length).bsearch(target);
  } else {
    return this.slice(0, half).bsearch(target);
  }
};

a = [0,1,2,3,4,5,6]

console.log(a.bsearch(5));

Related

1. binarySearch(value)

   Array.prototype.binarySearch = function(value){
       var items = this;
       console.log(items.length);
       var startIndex  = 0;
       var stopIndex = items.length - 1;
       var middle = Math.floor((stopIndex + startIndex)/2);
       while(items[middle] != value && startIndex < stopIndex){
           if (value < items[middle]){
               stopIndex = middle - 1;
   ...
   

2. binarySearchbinaryIndexOf;

   function binaryIndexOf(searchElement) {
       'use strict';
       var minIndex = 0;
       var maxIndex = this.length - 1;
       var currentIndex = -1;
       var currentElement;
       while (minIndex <= maxIndex) {
           currentIndex = (minIndex + maxIndex) / 2 | 0;
           currentElement = this[currentIndex];
   ...
   

3. binarySearchbinarySearch(val, from, to)

   Array.prototype.binarySearch = function binarySearch(val, from, to){
       if (from === undefined) {
           from = 0;
       if (to === undefined) {
           to = this.length-1;
       var mid = Math.ceil((from+to)/2),
           midVal = this[mid];
   ...
   

4. binary_search(val, left, right)

   Array.prototype.binary_search = function(val, left, right) {
       if (typeof left === 'undefined') left = 0;
       if (typeof right === 'undefined') right = this.length - 1;
       if (left > right) return null;
       var mid = (left + right) >> 1;
       if (val == this[mid]) {
           return mid;
       } else if (val > this[mid]) {
           return this.binary_search(val, mid + 1, right);
   ...
   

5. binarysearch(i)

   Array.prototype.binarysearch = function (i) {
       var l = 0, u = this.length,  m;
       while ( l <= u ) {
           m = ((l+u) >> 1);
           if ( i > this[m].i ) {
               l = m+1;
           } else {
               u = (i == this[m]) ? -2 : m - 1;
       return (u == -2) ? m : -1;
   };