Compilare: user.cpp: In function ‘int main()’: user.cpp:103:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rangemode.in","r",stdin); ^ user.cpp:104:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rangemode.out","w",stdout); ^ user.cpp: In function ‘int read()’: user.cpp:42:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] inline int read(){int x;scanf(" %d",&x);return x;} ^