#define SWAP(A, B) { int t = A; A = B; B = t; }

void bubblesort(int *a, int n)
{
  int j, nn;

  do {
    nn = 0;
    for (j = 1; j < n; ++j)
      if (a[j-1] > a[j]) {
        SWAP( a[j-1], a[j] );
        nn = j;
      }
    n = nn;
  } while (n);
}