Compilare: user.cpp: In member function ‘bool SAT::solve()’: user.cpp:65:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < comp.size(); i++) { ^ user.cpp: In member function ‘int SAT::get_color()’: user.cpp:119:17: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘int main()’: user.cpp:165:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("2sat.in","r",stdin); ^ user.cpp:166:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("2sat.out","w",stdout); ^ user.cpp:168:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:171:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^