Bubblesort (int data[],int n) {
   int tmp,i,j;

   for (i=0; i<n-1; i++) {
       for (j=0; j<n-i-1; j++)
            if (data[j] > data[j+1]) {
               tmp = data[j];
               data[j] = data[j+1];
               data[j+1] = tmp;
           }
   }
}