Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:22:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[nod].size(); i ++) ^ user.cpp:30:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < V[vec.first].size(); j ++) ^ user.cpp:42:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[nod].size(); i ++) ^ user.cpp:52:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < V[vec.first].size(); j ++) ^ user.cpp:69:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[nod].size(); i ++) ^ user.cpp:80:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < V[vec.first].size(); j ++) ^ user.cpp:90:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < V[vec.first].size(); j ++) ^ user.cpp: In function ‘int main()’: user.cpp:110:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("drumuri.in" ,"r", stdin ); ^ user.cpp:111:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("drumuri.out","w", stdout); ^ user.cpp:113:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &N, &M); ^ user.cpp:117:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &X, &Y); ^