Compilare: user.cpp: In member function ‘void trie::insert(char*, int)’: user.cpp:24:19: warning: NULL used in arithmetic [-Wpointer-arith] if (s[0]==NULL){ ^ user.cpp: In function ‘void antibfs()’: user.cpp:92:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<crt-> nrc.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:98:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("ahocorasick.in","r",stdin); ^ user.cpp:99:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("ahocorasick.out","w",stdout); ^ user.cpp:103:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(cuv); ^ user.cpp:104:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n",&n); ^ user.cpp:107:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/ccngWB5R.o: In function `main': user.cpp:(.text.startup+0x75): warning: the `gets' function is dangerous and should not be used.