foo.c: In function 'main':
foo.c:10:6: warning: unused variable 'k' [-Wunused-variable]
   10 |  int k = 0;
      |      ^
foo.c:13:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   13 |  scanf("%d", &n);
      |  ^~~~~~~~~~~~~~~
foo.c:16:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   16 |   scanf("%lf", &a[i]);
      |   ^~~~~~~~~~~~~~~~~~~

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