Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:27:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graf1[x].size();i++) ^ user.cpp: In function ‘void dfs_inv(int)’: user.cpp:39:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<graf2[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:64:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();i++) ^ user.cpp: In function ‘void citire()’: user.cpp:14:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &m); ^ user.cpp:18:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &x, &y); ^ user.cpp: In function ‘int main()’: user.cpp:57:34: 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); ^