foo.cc: In function 'int main()':
foo.cc:25:5: error: 'printf' was not declared in this scope
   25 |     printf("%d",icount);
      |     ^~~~~~
foo.cc:1:1: note: 'printf' is defined in header '<cstdio>'; did you forget to '#include <cstdio>'?
  +++ |+#include <cstdio>
    1 | int Do(int *pia,int isize)

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