Eroare de compilare: main.cpp: In function 'void insert(char*, arb*)': main.cpp:21:12: warning: NULL used in arithmetic [-Wpointer-arith] if(*c==NULL) ^~~~ main.cpp: In function 'void del(char*, arb*)': main.cpp:37:12: warning: NULL used in arithmetic [-Wpointer-arith] if(*c==NULL) ^~~~ main.cpp: In function 'int find_ap(char*, arb*)': main.cpp:46:14: warning: NULL used in arithmetic [-Wpointer-arith] if((*c)==NULL) ^~~~ main.cpp: In function 'int find_max(char*, arb*, int)': main.cpp:55:14: warning: NULL used in arithmetic [-Wpointer-arith] if((*c)==NULL || nod->next[ (*c)-'a'] == NULL || nod->next[ (*c)-'a']->trec ==0) ^~~~ main.cpp: In function 'int main()': main.cpp:70:16: error: no match for 'operator>' (operand types are 'std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}' and 'char [25]') while(f>>op>x) ~~~~~^~ In file included from /usr/include/c++/6/bits/stl_algobase.h:64:0, from /usr/include/c++/6/bits/char_traits.h:39, from /usr/include/c++/6/ios:40, from /usr/include/c++/6/ostream:38, from /usr/include/c++/6/iostream:39, from main.cpp:1: /usr/include/c++/6/bits/stl_pair.h:454:5: note: candidate: template<class _T1, class _T2> constexpr bool std::operator>(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&) operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) ^~~~~~~~ /usr/include/c++/6/bits/stl_pair.h:454:5: note: template argument deduction/substitution failed: main.cpp:70:17: note: 'std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}' is not derived from 'const std::pair<_T1, _T2>' while(f>>op>x) ^ In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0, from /usr/include/c++/6/bits/char_traits.h:39, from /usr/include/c++/6/ios:40, from /usr/include/c++/6/ostream:38, from /usr/include/c++/6/iostream:39, from main.cpp:1: /usr/include/c++/6/bits/stl_iterator.h:310:5: note: candidate: template<class _Iterator> bool std::operator>(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&) operator>(const reverse_iterator<_Iterator>& __x, ^~~~~~~~ /usr/include/c++/6/bits/stl_iterator.h:310:5: note: template argument deduction/substitution failed: main.cpp:70:17: note: 'std::basic_istream<char>::__istream_type {aka std::basic_istream<char>}' is not derived from 'const std::reverse_iterator<_Iterator>' while(f>>op>x) ^ In file included from /usr/include/c++/6/bits/stl_algobase.h:67:0, from /usr/include/c++/6/bits/char_traits.h:39, from /usr/include/c++/6/ios:40, from /usr/include/c++/6/ostream:38, Non zero exit status: 1