Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:20:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < V[u].size() ; i++){ ^ user.cpp: In function ‘void solve()’: user.cpp:87:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < query.size() ; i++){ ^ user.cpp: At global scope: user.cpp:104:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main(){ ^ user.cpp: In function ‘void load_graph()’: user.cpp:60:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:63:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&u); ^ user.cpp: In function ‘void read_query()’: user.cpp:70:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&q); ^ user.cpp:73:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&a,&b,&c); ^ user.cpp:76:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp:79:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^