Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:36:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < G[u].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:81:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("atac.in" , "r" , stdin); ^ main.cpp:82:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("atac.out" , "w" , stdout); ^ main.cpp:84:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d" , &n , &m , &p); ^ main.cpp:87:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &x , &y); ^ main.cpp:92:58: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d%d" , &xc , &yc , &A , &B , &C , &D); ^