Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:21:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<q[nod].size();i++) ^ user.cpp:36:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ^ user.cpp: In function ‘void dfs1(int)’: user.cpp:63:18: 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, int)’: user.cpp:70:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<q1[nod].size();i++) ^ user.cpp:83:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:109:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<q[i].size();j++) ^ user.cpp:89:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker2.in","r",stdin); ^ user.cpp:90:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker2.out","w",stdout); ^ user.cpp:92:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:95:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&c); ^ user.cpp:101:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&c); ^