Sort an array based on another array of integers

Question

Let\'s say I have an array: [0,3,4,2,5,1].

What I want to do is sort an array such as:

[\"one\", \"two\", \"three\", \"four\", \"five\",         


        

Answer 1

You can use first array as directory for sorting second one using map method:

const firstArray = [0, 3, 4, 2, 5, 1];
const secondArray = ['one', 'two', 'three', 'four', 'five', 'six'];

const result = firstArray.map((item) => {
 return secondArray[item];
});
// result = ["one", "four", "five", "three", "six", "two"]

Answer 2

class test1
{
  public static String[] sort(int[] array,String[] str)
  {
    String[] out=new String[str.length];
    for(int i=0;i<str.length;i++)
    {
      out[i]=str[array[i]];
    }
    return out;
  }
}

Answer 3

orderedArray= function(arr,order){
    return  order.map(function(itm){return arr[itm]});
}

var sequence= [0, 3, 4, 2, 5, 1],arr=["one","two","three","four","five","six"]

arr=new orderedArray(arr,sequence);

/*  returned value: (Array)
one,four,five,three,six,two
*/

//You can make the order an unindexed property of the array, // and call array.ordered()

Array.prototype.ordered= function(order){
    var arr= this;
    order=order || this.order;
    return order.map(function(itm){
        return arr[itm];
    });
}


var arr= ["one","two","three","four","five","six"],
sequence= [0, 3, 4, 2, 5, 1];

arr.order=sequence;

arr.ordered()

/*  returned value: (Array)
one,four,five,three,six,two
*/

Answer 4

let inds = [0,3,4,2,5,1];
let x = ["one", "two", "three", "four", "five", "six"];
let x2 = [];  //Output
inds.forEach(ind => x2.push(x[ind]));
x2
//(6) ["one", "four", "five", "three", "six", "two"]

Answer 5

I was asked this on a phone interview. Then do it without creating another array, supposing the array is very large. I don't know if this is the answer since I wasn't able to do on the call (damn!), but here's what I came up with.

var my_obj_array = ['a', 'b', 'c', 'd'];
var my_indicies = [3, 1, 0, 2];
// desired result ['d', 'b', 'a', 'c']

var temp = {};
for (var i = 0; i < my_indicies.length; i++) {
    temp[i] = my_obj_array[i];  // preserve
    var j = my_indicies[i];
    if (j in temp) {
        my_obj_array[i] = temp[j];
        delete temp[j];
    } else {
        my_obj_array[i] = my_obj_array[j];
    }
}

http://jsfiddle.net/innerb/RENjW/

Answer 6

You can do something like this:

function getSorted(arr, sortArr) {
  var result = [];
  for (var i = 0; i < arr.length; i++) {
    console.log(sortArr[i], arr[i]);
    result[i] = arr[sortArr[i]];
  }
  return result;
}
var arr = ["one", "two", "three", "four", "five", "six"];
var sortArr = [0, 3, 4, 2, 5, 1];
alert(getSorted(arr, sortArr));

Note: this assumes the arrays you pass in are equivalent in size, you'd need to add some additional checks if this may not be the case.