Compilare: main.cpp: In function 'int main()': main.cpp:4:50: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] #define FL(nm) do { freopen(nm ".in", "r", stdin); freopen(nm ".out", "w", stdout); } while (false) ^ main.cpp:13:5: note: in expansion of macro 'FL' FL("texttrim"); ^~ main.cpp:4:83: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] #define FL(nm) do { freopen(nm ".in", "r", stdin); freopen(nm ".out", "w", stdout); } while (false) ^ main.cpp:13:5: note: in expansion of macro 'FL' FL("texttrim"); ^~ main.cpp:17:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &spw); ^ main.cpp:19:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", width + i); ^ main.cpp:21:25: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(s, mxN, stdin); ^ main.cpp:25:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] ull w; scanf("%llu", &w); w -= 2; ^