Compilare: user.cpp: In function ‘std::pair<std::pair<int, int>, std::pair<int, int> > update_interval(int, int)’: user.cpp:172:9: warning: unused variable ‘l’ [-Wunused-variable] int l = st, r = dr; ^ user.cpp:172:17: warning: unused variable ‘r’ [-Wunused-variable] int l = st, r = dr; ^ user.cpp: In function ‘int main()’: user.cpp:218:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zeap.in", "r", stdin); ^ user.cpp:219:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zeap.out", "w", stdout); ^ user.cpp:231:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &x); ^ user.cpp:239:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &x); ^ user.cpp:251:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &x); ^