Compilare: user.cpp: In function ‘int main()’: user.cpp:41:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < st.size(); ++i) ^ user.cpp:52:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < dr.size(); ++i) ^ user.cpp:16:35: 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); ^ user.cpp:17:37: 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); ^ user.cpp:20:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:23:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y1, &y2); ^