Compilare: main.cpp: In function 'void A(N*)': main.cpp:23:16: warning: array subscript has type 'char' [-Wchar-subscripts] if(!r->l[*k]) ^ main.cpp:24:16: warning: array subscript has type 'char' [-Wchar-subscripts] r->l[*k]=new N(); ^ main.cpp:25:16: warning: array subscript has type 'char' [-Wchar-subscripts] A(r->l[*k++]); ^ main.cpp: In function 'int main()': main.cpp:29:118: 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),freopen("ahocorasick.out","w",stdout),fgets(e,1000001,stdin),scanf("%d\n",&n); ^ main.cpp:29:118: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:29:118: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:29:118: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] main.cpp:31:38: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(a,10001,stdin),k=a,A(r); ^