Compilare: main.cpp: In function 'int main()': main.cpp:88:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<v1.size();++i) ~^~~~~~~~~~ main.cpp:104:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<v2.size();++i) ~^~~~~~~~~~ main.cpp:57:33: 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:58:35: 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:61:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:65:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y1,&y2); ^