foo.cc: In function 'int main()':
foo.cc:8:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    8 |   scanf("%d",&a[i]);
      |   ~~~~~^~~~~~~~~~~~
foo.cc:21:8: warning: 'mid' may be used uninitialized in this function [-Wmaybe-uninitialized]
   21 |  cout<<mid;
      |        ^~~

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