p24.spn

function rrot(a, begin, k) {
  var n = k - 1;
  var tmp = a[begin + n];
  for var i = n; i > 0; i-- {
    a[begin + i % k] = a[begin + (i - 1) % k];
  }
  a[begin] = tmp;
}

function toFact(n, ndigs) {
  var r = {};
  for var i = 2; i < ndigs + 2; i++ {
    r[sizeof r] = n % i;
    n /= i;
  }

  return r;
}

function toPerm(n, arr) {
  var digits = toFact(n, sizeof arr - 1);

  for var j = 0, i = sizeof digits - 1; i >= 0; i-- {
    var idx = digits[i];
    rrot(arr, j++, idx + 1);
  }

  return arr;
}

var a = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
toPerm(999999, a);

for var i = 0; i < sizeof a; i++ {
  printf("%d", a[i]);
}
print();