Compilare: main.cpp: In function 'int main(int, char**)': main.cpp:5:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define FOR(i, n) for(int (i)=0; (i)<(n); (i)++) ~~~^~~~ main.cpp:76:5: note: in expansion of macro 'FOR' FOR(n, C.size()) ^~~ main.cpp:72:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbori2.in", "r", stdin); ^ main.cpp:73:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbori2.out", "w", stdout); ^