foo.cc: In function 'int work2()':
foo.cc:17:20: warning: integer overflow in expression of type 'int' results in '2147483647' [-Woverflow]
   17 |     int ans=(1<<31)-1;
      |             ~~~~~~~^~
foo.cc:21:13: error: 'memset' was not declared in this scope
   21 |             memset(book,0,sizeof(book));
      |             ^~~~~~
foo.cc:3:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    2 | #include <algorithm>
  +++ |+#include <cstring>
    3 | using namespace std;

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