Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[Nod].size(); ++i) ^ user.cpp: In function ‘void dfs2(int)’: user.cpp:24:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < b[Nod].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:52:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < Sol[i].size(); ++j) ^ user.cpp:30:34: 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:31:36: 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:32:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:35:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^