foo.cc: In function 'int main()':
foo.cc:54:2: error: 'memset' was not declared in this scope
   54 |  memset(a, '.', sizeof(a)); memset(b, '.', sizeof(b));
      |  ^~~~~~
foo.cc:2:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    1 | #include<iostream>
  +++ |+#include <cstring>
    2 | using namespace std;

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