Compilare: user.cpp: In function ‘void solve()’: user.cpp:79:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] {for(j=0;j<C[i].size();j++) ^ user.cpp: In function ‘void dfs(int)’: user.cpp:95:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<G[nod].size();i++) ^ user.cpp: In function ‘void dft(int)’: user.cpp:107:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<GT[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:140:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<sol[i].size();j++) ^ user.cpp:119:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out","wt",stdout); ^ user.cpp: In function ‘void read()’: user.cpp:11:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in","rt",stdin); ^ user.cpp:12:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:17:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^