Compilare: user.cpp: In function ‘void insert(trie*, char*)’: user.cpp:20:13: warning: NULL used in arithmetic [-Wpointer-arith] {if(*s==NULL) ^ user.cpp:22:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(nod->fii[*s]==NULL) ^ user.cpp:23:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] nod->fii[*s]=new trie; ^ user.cpp:24:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] insert(nod->fii[*s],s+1); ^ user.cpp: In function ‘int xoreala(trie*, char*, int)’: user.cpp:27:13: warning: NULL used in arithmetic [-Wpointer-arith] {if(*s==NULL) ^ user.cpp:29:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(nod->fii[*s]==NULL) ^ user.cpp:40:42: warning: array subscript has type ‘char’ [-Wchar-subscripts] return pow(a)+xoreala(nod->fii[*s],s+1,a-1); ^ user.cpp: In function ‘int main()’: user.cpp:44:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen ("xormax.in","r",stdin); ^ user.cpp:45:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("xormax.out","w",stdout); ^ user.cpp:47:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:48:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp:66:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf("%d",&x); ^