var arr=[];

var x=[];

var y;

​

for(var i=0;i<4;i++){

  arr[i]=5*(i+1);

}

​

var canvas = document.getElementById('myCanvas');

var context = canvas.getContext('2d');

var centerX = 0;

var centerY = 90;

var radius = 70;

var temp;

var xar=[];

var constructed = [];

​

​

for(var i=0;i<4;i++){

  centerX=centerX+100;

  context.beginPath();

  context.arc(centerX, centerY, 50, 0, 2 * Math.PI, false);

  context.fillStyle = 'green';

  context.fill();

  context.lineWidth = 5;

  context.strokeStyle = '#003300';

  context.stroke();

  context.fillStyle="black";

  context.fillText(arr[i],centerX,centerY);

}

​

function go(){

  for(i=0; i<4; i++){

    temp=parseInt(document.getElementById("one"+i).value);

    xar.push(temp);

  }

  // My part START

  var filtered = xar.filter(function(number){

    return contains(arr, number);

  });

​

  arr.forEach(function(el, key) {

    filtered.forEach(function(cel,ckey){

      if (el === cel){

        constructed[key] = el;

      }

    })

  });

  var dif = difference(xar, constructed);

  for(var k=0; k<4; k++){

    var cval = constructed[k];

    if (cval === undefined){

      constructed[k] = dif[0];

      dif.shift();

    }

  }

  // My part END

  var xnext=0;

  for(var i=0; i<4; i++){

    xnext=xnext+100;

    context.beginPath();

    context.arc(xnext, 190, 50, 0, 2 * Math.PI, false);

    context.fillStyle = 'green';

    context.fill();

    context.lineWidth = 5;

    context.strokeStyle = '#003300';

    context.stroke();

    context.fillStyle="black";

    context.fillText(constructed[i],xnext,190);

    if(xar[i]==arr[i]){

      context.arc(xnext, 190, 50, 0, 2 * Math.PI, false);

    }

  }

}

​

//// My Helpers

function contains(a, obj) {

    var i = a.length;

    while (i--) {

       if (a[i] === obj) {

           return true;

       }

    }

    return false;

}

​

function difference(a1, a2) {

  var result = [];

  for (var i = 0; i < a1.length; i++) {

    if (a2.indexOf(a1[i]) === -1) {

      result.push(a1[i]);

    }

  }

  return result;

}

​

Object.prototype.getKeyByValue = function( value ) {

    for( var prop in this ) {

        if( this.hasOwnProperty( prop ) ) {

             if( this[ prop ] === value )

                 return prop;

        }

    }

}