Compilare: user.cpp: In function ‘bool check(int, int&)’: user.cpp:74:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(dr >= a[i].y) continue ; ~~~^~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:90:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("light.out", "w", stdout); ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:14:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, fin); ^