code: public static void fastinverseDelta(int[] data) {
                  int sz0 = data.length / 4 * 4;
                  int i = 1;
                  if (sz0 >= 4) {
                          int a = data[0];
                          for (; i < sz0 - 4; i += 4) {
                                  a = data[i] += a;
                                  a = data[i + 1] += a;
                                  a = data[i + 2] += a;
                                  a = data[i + 3] += a;
                          }
                  }
  
                  for (; i != data.length; ++i) {
                          data[i] += data[i - 1];
                  }
          }
docs: Undo differential coding (in-place). Effectively computes a prefix
  sum. Like inverseDelta, only faster.
  
  @param data
  to be modified