Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:26:33: 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 ‘void afisare()’: user.cpp:51:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<sol[i].size();j++) ^ user.cpp: In function ‘void citire()’: user.cpp:13:29: 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:17:33: 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:59:34: 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:60:36: 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); ^