foo.c: In function 'qsort':
foo.c:4:29: warning: unused variable 'mid' [-Wunused-variable]
  int bas=a[lft],l=lft,r=rht,mid=(lft+rht)/2;
                             ^~~
foo.c: In function 'main':
foo.c:47:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ^~~~~~~~~~~~~~
foo.c:48:22: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=0;i<n;++i)scanf("%d",a+i);
                      ^~~~~~~~~~~~~~~

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