Compilare: user.cpp: In function ‘int main()’: user.cpp:101:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sol.size();i++) ^ user.cpp: In function ‘void read()’: user.cpp:17:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&n,&m,&x,&y); ^ user.cpp:21:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ",&a,&b); ^ user.cpp: In function ‘int main()’: user.cpp:71:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in","r",stdin); ^ user.cpp:72:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out","w",stdout); ^