Compilare: user.cpp: In function ‘void idfs(int, int)’: user.cpp:45:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<invg[nod].size(); i++) ^ user.cpp: In function ‘void dfs(int)’: user.cpp:58:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<grph[nod].size(); i++) ^ user.cpp: In function ‘void finisare()’: user.cpp:96:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<mele[j].size(); i++) ^ user.cpp: In function ‘void read_data()’: user.cpp:13:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:19:22: 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:104:29: 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:105:31: 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); ^