Compilare: user.cpp: In function ‘void DFS1(int)’: user.cpp:16:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < G[Node].size();i++) ^ user.cpp: In function ‘void DFS2(int)’: user.cpp:28:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < TG[Node].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:65:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0;j < SCC[i].size();j++) ^ user.cpp:35:32: 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:36:34: 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); ^ user.cpp:38:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&N,&M); ^ user.cpp:43:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&A,&B); ^