crazy.cpp:62:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
62 | main() {
| ^~~~
crazy.cpp: In function 'int main()':
crazy.cpp:4:48: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
4 | #define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~
crazy.cpp:63:2: note: in expansion of macro 'file'
63 | file("crazy");
| ^~~~
crazy.cpp:4:77: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
4 | #define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
crazy.cpp:63:2: note: in expansion of macro 'file'
63 | file("crazy");
| ^~~~