Selectsort (int data[],int n) {
   int min,tmp,i,j,min_id;

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