Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:24:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<G[node].size();++i) ^ user.cpp: In function ‘void dfst(int)’: user.cpp:31:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<GT[node].size();++i) ^ user.cpp: In function ‘void write()’: user.cpp:44:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<sol[i].size();++j) ^ user.cpp: In function ‘void read()’: user.cpp:11:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in","r",stdin); ^ user.cpp:12:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:16:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ user.cpp: In function ‘void write()’: user.cpp:40:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out","w",stdout); ^