Compilare: user.cpp: In function ‘int main()’: user.cpp:54:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<H.size();i++) ^ user.cpp:58:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<hsh[lin].size();j++) ^ user.cpp:32:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("litere2.in","r",stdin); ^ user.cpp:33:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("litere2.out","w",stdout); ^ user.cpp:34:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sir+1); ^ /tmp/cc9pmUUV.o: In function `main': user.cpp:(.text.startup+0x56): warning: the `gets' function is dangerous and should not be used.