foo.cc: In function 'float swap(int&, int&)':
foo.cc:10:1: warning: no return statement in function returning non-void [-Wreturn-type]
   10 | }
      | ^
foo.cc: In function 'int main()':
foo.cc:14:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   14 |  scanf("%d,%d",&x,&y);
      |  ~~~~~^~~~~~~~~~~~~~~

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