Compilare: user.cpp: In function ‘void go_visit(int, int, int)’: user.cpp:11:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod[pos].size();i++) ~^~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:38:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod[d].size();i++) ~^~~~~~~~~~~~~~ user.cpp:40:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod[c].size();i++) ~^~~~~~~~~~~~~~ user.cpp:42:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod[v].size();i++) ~^~~~~~~~~~~~~~ user.cpp:20:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fantasy.in","r",stdin); ^ user.cpp:21:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fantasy.out","w",stdout); ^ user.cpp:22:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp:26:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&n,&d,&c,&v); ^ user.cpp:31:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^