Compilare: user.cpp: In function ‘void read()’: user.cpp:27:13: warning: unused variable ‘conva’ [-Wunused-variable] int a,b,conva,convb,notconva,notconvb; ^ user.cpp:27:19: warning: unused variable ‘convb’ [-Wunused-variable] int a,b,conva,convb,notconva,notconvb; ^ user.cpp:27:25: warning: unused variable ‘notconva’ [-Wunused-variable] int a,b,conva,convb,notconva,notconvb; ^ user.cpp:27:34: warning: unused variable ‘notconvb’ [-Wunused-variable] int a,b,conva,convb,notconva,notconvb; ^ user.cpp: In function ‘void visit(int)’: user.cpp:42:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<G[u].size(); ++i) ^ user.cpp: In function ‘void createComponent(int, int)’: user.cpp:51:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<Gt[u].size(); ++i) ^ user.cpp: In function ‘bool sat2()’: user.cpp:82:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<componentVector[i].size(); j++) ^ user.cpp: In function ‘void read()’: user.cpp:26:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ^ user.cpp:31:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^ user.cpp: In function ‘int main()’: user.cpp:99:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("2sat.in","rt",stdin); ^ user.cpp:100:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("2sat.out","wt",stdout); ^