Nodejs Array Search Binary binarySearchbinaryIndexOf;

Method Source Code

/**//ww  w .j  a v  a  2s  .c  o m
 * Performs a binary search on the host array. This method can either be
 * injected into Array.prototype or called with a specified scope like this:
 * binaryIndexOf.call(someArray, searchElement);
 *
 * @param {*} searchElement The item to search for within the array.
 * @return {Number} The index of the element which defaults to -1 when not found.
 */
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];

        if (currentElement < searchElement) {
            minIndex = currentIndex + 1;
        }
        else if (currentElement > searchElement) {
            maxIndex = currentIndex - 1;
        }
        else {
            return currentIndex;
        }
    }

    return currentIndex;
}

Array.prototype.binarySearch = binaryIndexOf;

Related

1. binarySearch(searchElement)

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

2. binarySearch(val)

   Array.prototype.binarySearch = function(val){
     var min = 0;
     var max = this.length -1;
     var currentIndex;
     var currentElement;
     while (min <= max) {
       currentIndex = Math.floor((min +max) / 2);
       currentElement = this[currentIndex];
       if (currentElement > val) {
   ...
   

3. binarySearch(val)

   Array.prototype.binarySearch = function(val){
     var keeper = 0;
     var answer = -1;
     function recursive(arr){
       var len = arr.length;
       var start = Math.floor(len / 2);
       var current = arr[start];
       if (current === val){
         answer = start + keeper;
   ...
   

4. binarySearch(value)

   Array.prototype.binarySearch = function(value) {
       'use strict';
       if(!value){
           return null;
       var left = 0,
           right = this.length-1,
           find = false,
           middle = null;
   ...
   

5. 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;
   ...
   

6. 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];
   ...
   

7. 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);
   ...
   

8. 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;
   };
   

9. bsearch(target)

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