Compilare: main.cpp: In function 'int main()': main.cpp:49:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(register int i=0;i<v.size();i++) ~^~~~~~~~~ main.cpp:62:27: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=] printf("%d",ans.size()); ^ main.cpp:33:12: warning: unused variable 'u1' [-Wunused-variable] double u1,u2; ^~ main.cpp:33:15: warning: unused variable 'u2' [-Wunused-variable] double u1,u2; ^~ main.cpp:30:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rays.in","r",stdin); ^ main.cpp:31:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rays.out","w",stdout); ^ main.cpp:34:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:40:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y1,&y2); ^