node-bisection

bisection

lib/bisection.js

Calculates the index of the Array where item X should be placed, assuming the Array is sorted.

  • param: Array array The array containing the items.

  • param: Number x The item that needs to be added to the array.

  • param: Number low Inital Index that is used to start searching, optional.

  • param: Number high The maximum Index that is used to stop searching, optional.

  • returns: Number the index where item X should be placed

function bisection(array, x, low, high){
  // The low and high bounds the inital slice of the array that needs to be searched
  // this is optional
  low || (low = 0);
  high || (high = array.length);
  
  var mid;
    
  while(low < high){
    mid = (low + high) >> 1;
    
    if (x < array[mid]){
      high = mid;
    } else {
      low = mid + 1;
    }
  }
  
  return low;
};

A right bisection is default, so just reference the same function

bisection.right = bisection;

Calculates the index of the Array where item X should be placed, assuming the Array is sorted. ##

  • param: Array array The array containing the items.

  • param: number x The item that needs to be added to the array.

  • param: number low Inital Index that is used to start searching, optional.

  • param: number high The maximum Index that is used to stop searching, optional.

  • return: number the index where item X should be placed

bisection.left = function left( array, x, low , high ){
  // The low and high bounds the inital slice of the array that needs to be searched
  // this is optional
  low || (low = 0);
  high || (high = array.length);
  
  var mid;
  
  while(low < high){
    mid = (low + high) >> 1;
  
    if(x < array[mid]){
      low = mid + 1;
    } else {
      high = mid;
    }
  }
  
  return low;
};

Library version

bisection.version = '0.0.1';

module.exports = bisection;