foo.cc: In function 'int main()':
foo.cc:6:10: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'int' [-Wformat=]
    6 |  scanf("%d", n);
      |         ~^   ~
      |          |   |
      |          |   int
      |          int*
foo.cc:6:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%d", n);
      |  ~~~~~^~~~~~~~~
foo.cc:6:7: warning: 'n' is used uninitialized in this function [-Wuninitialized]
    6 |  scanf("%d", n);
      |  ~~~~~^~~~~~~~~

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