Compilare: user.cpp: In function ‘int main()’: user.cpp:71:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(r);i++) { ^ user.cpp:64:36: 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:67:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(r); ^ /tmp/ccLgr2N1.o: In function `main': user.cpp:(.text.startup+0x51): warning: the `gets' function is dangerous and should not be used.