Compilare: user.cpp: In function ‘int main()’: user.cpp:50:10: warning: unused variable ‘i’ [-Wunused-variable] long i, j; ^ user.cpp:50:13: warning: unused variable ‘j’ [-Wunused-variable] long i, j; ^ user.cpp:51:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("emm.in", "r", stdin); ^ user.cpp:52:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("emm.out", "w", stdout); ^ user.cpp:53:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/cciqEIuS.o: In function `main': user.cpp:(.text.startup+0x53): warning: the `gets' function is dangerous and should not be used.