Compilare: user.cpp: In function ‘int main()’: user.cpp:14:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( IN , "r" , stdin ) ; ^ user.cpp:15:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( OUT , "w" , stdout ) ; ^ user.cpp:17:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d\n" , &t ) ; ^ user.cpp:19:25: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets ( sir + 1 ); ^ /tmp/cclDMcOL.o: In function `main': user.cpp:(.text.startup+0x82): warning: the `gets' function is dangerous and should not be used.