foo.cc: In function 'int main()':
foo.cc:5:1: error: 'scanf_s' was not declared in this scope
    5 | scanf_s("%d", &T);
      | ^~~~~~~
foo.cc:11:1: error: 'printf' was not declared in this scope
   11 | printf("%0.4f\n", sum);
      | ^~~~~~
foo.cc:1:1: note: 'printf' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?
  +++ |+#include <cstdio>
    1 | int main(){

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