pivot-sort.js

var a = [0, 5, 2, 1, 3];
var p = 2; // pivot

function diff(a, b) {
  return Math.abs(a - b);
}

function sort(a, b) {
  var ax = diff(a, p);
  var bx = diff(b, p);
  if (ax > bx) return 1;
  if (ax < bx) return -1;
  return 0;
}

console.log(a.sort(sort));