code: def _radixPass(a, b, r, n, K):
      c = _array("i", [0] * (K + 1))
      for i in range(n):
          c[r[a[i]]] += 1
      sum = 0
      for i in range(K + 1):
          t = c[i]
          c[i] = sum
          sum += t
      for a_i in a[:n]:
          b[c[r[a_i]]] = a_i
          c[r[a_i]] += 1