Compilare: user.cpp: In function ‘int main()’: user.cpp:116:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("base3.in","r",stdin); ^ user.cpp:117:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("base3.out","w",stdout); ^ user.cpp:120:13: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sa); ^ user.cpp:121:13: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sb); ^ user.cpp:122:13: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sc); ^ /tmp/ccz1Q8yd.o: In function `main': user.cpp:(.text.startup+0x54): warning: the `gets' function is dangerous and should not be used.