subsequence.cpp:63:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
63 | main() {
| ^
subsequence.cpp: In function 'int main()':
subsequence.cpp:23:48: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
23 | #define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~
subsequence.cpp:64:3: note: in expansion of macro 'file'
64 | file("paint");
| ^~~~
subsequence.cpp:23:77: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
23 | #define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
subsequence.cpp:64:3: note: in expansion of macro 'file'
64 | file("paint");
| ^~~~