Compilare: user.cpp: In function ‘int main()’: user.cpp:12:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("reteta2.in","r",stdin); ^ user.cpp:13:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("reteta2.out","w",stdout); ^ user.cpp:15:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sir+1); ^ user.cpp:41:29: warning: ‘a’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(int j=1;j<=k;j++) ^ /tmp/cc6iWs1p.o: In function `main': user.cpp:(.text.startup+0x56): warning: the `gets' function is dangerous and should not be used.