123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141 |
- /*
- Copyright (c) Alexander Zaitsev <zamazan4ik@gmail.com>, 2016
- Distributed under the Boost Software License, Version 1.0. (See
- accompanying file LICENSE_1_0.txt or copy at
- http://www.boost.org/LICENSE_1_0.txt)
- See http://www.boost.org/ for latest version.
- */
- /// \file is_palindrome.hpp
- /// \brief Checks the input sequence on palindrome.
- /// \author Alexander Zaitsev
- #ifndef BOOST_ALGORITHM_IS_PALINDROME_HPP
- #define BOOST_ALGORITHM_IS_PALINDROME_HPP
- #include <iterator>
- #include <functional>
- #include <cstring>
- #include <boost/config.hpp>
- #include <boost/range/begin.hpp>
- #include <boost/range/end.hpp>
- namespace boost { namespace algorithm {
- /// \fn is_palindrome ( BidirectionalIterator begin, BidirectionalIterator end, Predicate p )
- /// \return true if the entire sequence is palindrome
- ///
- /// \param begin The start of the input sequence
- /// \param end One past the end of the input sequence
- /// \param p A predicate used to compare the values.
- ///
- /// \note This function will return true for empty sequences and for palindromes.
- /// For other sequences function will return false.
- /// Complexity: O(N).
- template <typename BidirectionalIterator, typename Predicate>
- bool is_palindrome(BidirectionalIterator begin, BidirectionalIterator end, Predicate p)
- {
- if(begin == end)
- {
- return true;
- }
- --end;
- while(begin != end)
- {
- if(!p(*begin, *end))
- {
- return false;
- }
- ++begin;
- if(begin == end)
- {
- break;
- }
- --end;
- }
- return true;
- }
- /// \fn is_palindrome ( BidirectionalIterator begin, BidirectionalIterator end )
- /// \return true if the entire sequence is palindrome
- ///
- /// \param begin The start of the input sequence
- /// \param end One past the end of the input sequence
- ///
- /// \note This function will return true for empty sequences and for palindromes.
- /// For other sequences function will return false.
- /// Complexity: O(N).
- template <typename BidirectionalIterator>
- bool is_palindrome(BidirectionalIterator begin, BidirectionalIterator end)
- {
- return is_palindrome(begin, end,
- std::equal_to<typename std::iterator_traits<BidirectionalIterator>::value_type> ());
- }
- /// \fn is_palindrome ( const R& range )
- /// \return true if the entire sequence is palindrome
- ///
- /// \param range The range to be tested.
- ///
- /// \note This function will return true for empty sequences and for palindromes.
- /// For other sequences function will return false.
- /// Complexity: O(N).
- template <typename R>
- bool is_palindrome(const R& range)
- {
- return is_palindrome(boost::begin(range), boost::end(range));
- }
- /// \fn is_palindrome ( const R& range, Predicate p )
- /// \return true if the entire sequence is palindrome
- ///
- /// \param range The range to be tested.
- /// \param p A predicate used to compare the values.
- ///
- /// \note This function will return true for empty sequences and for palindromes.
- /// For other sequences function will return false.
- /// Complexity: O(N).
- template <typename R, typename Predicate>
- bool is_palindrome(const R& range, Predicate p)
- {
- return is_palindrome(boost::begin(range), boost::end(range), p);
- }
- /// \fn is_palindrome ( const char* str )
- /// \return true if the entire sequence is palindrome
- ///
- /// \param str C-string to be tested.
- ///
- /// \note This function will return true for empty sequences and for palindromes.
- /// For other sequences function will return false.
- /// Complexity: O(N).
- bool is_palindrome(const char* str)
- {
- if(!str)
- return true;
- return is_palindrome(str, str + strlen(str));
- }
- /// \fn is_palindrome ( const char* str, Predicate p )
- /// \return true if the entire sequence is palindrome
- ///
- /// \param str C-string to be tested.
- /// \param p A predicate used to compare the values.
- ///
- /// \note This function will return true for empty sequences and for palindromes.
- /// For other sequences function will return false.
- /// Complexity: O(N).
- template<typename Predicate>
- bool is_palindrome(const char* str, Predicate p)
- {
- if(!str)
- return true;
- return is_palindrome(str, str + strlen(str), p);
- }
- }}
- #endif // BOOST_ALGORITHM_IS_PALINDROME_HPP
|