Compilare: user.cpp: In function ‘void Solve(int, int, int)’: user.cpp:27:9: warning: variable ‘l’ set but not used [-Wunused-but-set-variable] int l,r; ^ user.cpp:27:11: warning: variable ‘r’ set but not used [-Wunused-but-set-variable] int l,r; ^ user.cpp: In function ‘int main()’: user.cpp:50:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("photo.in","r",stdin); ^ user.cpp:51:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("photo.out","w",stdout); ^ user.cpp:53:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&a); ^ user.cpp:56:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&v[i].first,&v[i].second); ^