/in/foo.cc: In function 'int main()':
/in/foo.cc:33:34: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::queue<int>::size_type {aka long unsigned int}' [-Wformat=]
    printf ("Size = %d\n",q.size());
                                  ^
/in/foo.cc:41:8: warning: unused variable 'cnt' [-Wunused-variable]
    int cnt=0;
        ^~~