[рони]

var arr = '1 2 3 2 3 4 5 1 4 6'.match(/\d+/g);
var max = 4;
function pit(arr, max)
{
   var puddle = 0, min;
   for (var i = 0; i < arr.length; i++) {
       if(max <= +arr[i]) break;
       if(min == void 0 && arr[i + 1] <  arr[i]) min = arr[i];
       if(min != void 0 && arr[i] > min) min = void 0;
       if(min != void 0) puddle += min - arr[i];
   }
  return puddle
}

var num = pit(arr, max) ;
alert(num);