foo.cc: In function 'int main()':
foo.cc:16:31: warning: unknown conversion type character '\x0a' in format [-Wformat=]
   16 |                 printf("%.2lf%\n",b[i]*100.0/n);
      |                               ^~
foo.cc:16:38: warning: 'b' is used uninitialized [-Wuninitialized]
   16 |                 printf("%.2lf%\n",b[i]*100.0/n);
      |                                   ~~~^
foo.cc:6:16: note: 'b' declared here
    6 |         double b[10];
      |                ^

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