Compilare: main.cpp: In function 'int main()': main.cpp:11:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("interval.in","r",stdin); ^ main.cpp:12:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("interval.out","w",stdout); ^ main.cpp:13:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lli%lli%lli",&a,&b,&n); ^ main.cpp:16:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%lli%lli",&c,&k); ^