Compilare: user.cpp: In function ‘void bkt(int, bool)’: user.cpp:37:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(lvl == v.size()) ^ user.cpp:40:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v.size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:66:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("armonica.in", "r", stdin); ^ user.cpp:67:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("armonica.out", "w", stdout); ^ user.cpp:68:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &b); ^