Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:17:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[nod].size(); i++) ^ user.cpp: In function ‘void dfst(int)’: user.cpp:26:37: 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:65:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < C[i].size(); j++) ^ user.cpp:34:33: 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:35:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N,&M); ^ user.cpp:38:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x,&y); ^ user.cpp:60:34: 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); ^