Compilare: user.cpp: In function ‘int main()’: user.cpp:63:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(frB[A[i]]){ ^ user.cpp:64:58: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(last>0 && A[i]<st[last] && frA[st[last]]>=frB[st[last]]+1){ ^ user.cpp:64:73: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(last>0 && A[i]<st[last] && frA[st[last]]>=frB[st[last]]+1){ ^ user.cpp:65:29: warning: array subscript has type ‘char’ [-Wchar-subscripts] frB[st[last]]++; ^ user.cpp:69:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] frB[A[i]]--; ^ user.cpp:71:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] frA[A[i]]--; ^ user.cpp: In function ‘char nextch()’: user.cpp:13:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, fi); ^