stl_slist.h // Filename: stl_slist.h // Comment By: 凝霜 // E-mail: [email protected] // Blog: http://blog.csdn.net/mdl13412 /* * Copyright (c) 1997 * Silicon Graphics Computer Systems, Inc. * * Permission to use, copy, modify, distribute and sell this software * and its documentation for any purpose is hereby granted without fee, * provided that the above copyright notice appear in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation. Silicon Graphics makes no * representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied warranty. * */ /* NOTE: This is an internal header file, included by other STL headers. * You should not attempt to use it directly. */ #ifndef __SGI_STL_INTERNAL_SLIST_H #define __SGI_STL_INTERNAL_SLIST_H __STL_BEGIN_NAMESPACE #if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32) #pragma set woff 1174 #endif // 这个是链表结点的指针域 struct __slist_node_base { __slist_node_base* next; }; //////////////////////////////////////////////////////////////////////////////// // 将new_node插入到prev_node后面 //////////////////////////////////////////////////////////////////////////////// // 插入前 // 这个是prev_node 这个是new_node // ↓ ↓ // -------- -------- -------- -------- // ... | next |--->| next |-------->| next | ... | next | // -------- -------- -------- -------- // 插入后 // 这个是prev_node 这个是new_node // ↓ --------------------------------- ↓ // -------- -------- | -------- | -------- // ... | next |--->| next |--- -->| next | ... --->| next |--- // -------- -------- | -------- -------- | // ------------------------------------------- //////////////////////////////////////////////////////////////////////////////// inline __slist_node_base* __slist_make_link(__slist_node_base* prev_node, __slist_node_base* new_node) { new_node->next = prev_node->next; prev_node->next = new_node; return new_node; } // 获取指定结点的前一个结点 inline __slist_node_base* __slist_previous(__slist_node_base* head, const __slist_node_base* node) { while (head && head->next != node) head = head->next; return head; } inline const __slist_node_base* __slist_previous(const __slist_node_base* head, const __slist_node_base* node) { while (head && head->next != node) head = head->next; return head; } //////////////////////////////////////////////////////////////////////////////// // 将(first, last]链接到pos后面 //////////////////////////////////////////////////////////////////////////////// // 下面的例子是在同一链表进行操作的情况 // 操作前 // pos after before_first first before_last // ↓ ↓ ↓ ↓ ↓ // -------- -------- -------- -------- -------- -------- -------- // ... | next |--->| next |--->| next |--->| next |--->| next |--->| next |--->| next | ... // -------- -------- -------- -------- -------- -------- -------- // 操作后 // pos after before_first first before_last // ↓ ↓ ↓ ↓ ↓ // -------- -------- -------- -------- -------- -------- -------- // ... | next | ->| next |--->| next |-- | next |--->| next |--->| next | ->| next | ... // -------- | -------- -------- | -------- -------- -------- | -------- // | | | ↑ | | // ------|----------------------|------- | | // -----------------------|------------------------------- | // -------------------------------------- //////////////////////////////////////////////////////////////////////////////// inline void __slist_splice_after(__slist_node_base* pos, __slist_node_base* before_first, __slist_node_base* before_last) { if (pos != before_first && pos != before_last) { __slist_node_base* first = before_first->next; __slist_node_base* after = pos->next; before_first->next = before_last->next; pos->next = first; before_last->next = after; } } // 链表转置 inline __slist_node_base* __slist_reverse(__slist_node_base* node) { __slist_node_base* result = node; node = node->next; result->next = 0; while(node) { __slist_node_base* next = node->next; node->next = result; result = node; node = next; } return result; } // 这个是真正的链表结点 template <class T> struct __slist_node : public __slist_node_base { T data; }; struct __slist_iterator_base { typedef size_t size_type; typedef ptrdiff_t difference_type; typedef forward_iterator_tag iterator_category; __slist_node_base* node; __slist_iterator_base(__slist_node_base* x) : node(x) {} void incr() { node = node->next; } bool operator==(const __slist_iterator_base& x) const { return node == x.node; } bool operator!=(const __slist_iterator_base& x) const { return node != x.node; } }; // 链表迭代器, 关于迭代器参考<stl_iterator.h> // 由于是单向链表, 所以不能提供operator --(效率太低) // 同样也不能提供随机访问能力 template <class T, class Ref, class Ptr> struct __slist_iterator : public __slist_iterator_base { typedef __slist_iterator<T, T&, T*> iterator; typedef __slist_iterator<T, const T&, const T*> const_iterator; typedef __slist_iterator<T, Ref, Ptr> self; typedef T value_type; typedef Ptr pointer; typedef Ref reference; typedef __slist_node<T> list_node; __slist_iterator(list_node* x) : __slist_iterator_base(x) {} __slist_iterator() : __slist_iterator_base(0) {} __slist_iterator(const iterator& x) : __slist_iterator_base(x.node) {} reference operator*() const { return ((list_node*) node)->data; } #ifndef __SGI_STL_NO_ARROW_OPERATOR // 如果编译器支持‘->‘则重载, 详细见我在<stl_list.h>中的剖析 pointer operator->() const { return &(operator*()); } #endif /* __SGI_STL_NO_ARROW_OPERATOR */ self& operator++() { incr(); return *this; } self operator++(int) { self tmp = *this; incr(); return tmp; } }; #ifndef __STL_CLASS_PARTIAL_SPECIALIZATION inline ptrdiff_t* distance_type(const __slist_iterator_base&) { return 0; } inline forward_iterator_tag iterator_category(const __slist_iterator_base&) { return forward_iterator_tag(); } template <class T, class Ref, class Ptr> inline T* value_type(const __slist_iterator<T, Ref, Ptr>&) { return 0; } #endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */ // 计算链表长度, 时间复杂度O(n) inline size_t __slist_size(__slist_node_base* node) { size_t result = 0; for ( ; node != 0; node = node->next) ++result; return result; } template <class T, class Alloc = alloc> class slist { public: // 标记为‘STL标准强制要求‘的typedefs用于提供iterator_traits<I>支持 typedef T value_type; // STL标准强制要求 typedef value_type* pointer; // STL标准强制要求 typedef const value_type* const_pointer; typedef value_type& reference; // STL标准强制要求 typedef const value_type& const_reference; typedef size_t size_type; typedef ptrdiff_t difference_type; // STL标准强制要求 typedef __slist_iterator<T, T&, T*> iterator; // STL标准强制要求 typedef __slist_iterator<T, const T&, const T*> const_iterator; private: typedef __slist_node<T> list_node; typedef __slist_node_base list_node_base; typedef __slist_iterator_base iterator_base; // 这个提供STL标准的allocator接口 typedef simple_alloc<list_node, Alloc> list_node_allocator; // 创建一个值为x的结点, 其没有后继结点 static list_node* create_node(const value_type& x) { list_node* node = list_node_allocator::allocate(); __STL_TRY { construct(&node->data, x); node->next = 0; } __STL_UNWIND(list_node_allocator::deallocate(node)); return node; } // 析构一个结点的数据, 不释放内存 static void destroy_node(list_node* node) { destroy(&node->data); list_node_allocator::deallocate(node); } //////////////////////////////////////////////////////////////////////////////// // 在头结点插入n个值为x的结点 //////////////////////////////////////////////////////////////////////////////// // fill_initialize(size_type n, const value_type& x) // ↓ // _insert_after_fill(&head, n, x); // ↓ // for (size_type i = 0; i < n; ++i) // pos = __slist_make_link(pos, create_node(x)); // | // | // ↓ // create_node(const value_type& x) // list_node_allocator::allocate(); // construct(&node->data, x); //////////////////////////////////////////////////////////////////////////////// void fill_initialize(size_type n, const value_type& x) { head.next = 0; __STL_TRY { _insert_after_fill(&head, n, x); } __STL_UNWIND(clear()); } // 在头结点后面插入[first, last)区间内的结点, 注意是新建立结点 #ifdef __STL_MEMBER_TEMPLATES template <class InputIterator> void range_initialize(InputIterator first, InputIterator last) { head.next = 0; __STL_TRY { _insert_after_range(&head, first, last); } __STL_UNWIND(clear()); } #else /* __STL_MEMBER_TEMPLATES */ void range_initialize(const value_type* first, const value_type* last) { head.next = 0; __STL_TRY { _insert_after_range(&head, first, last); } __STL_UNWIND(clear()); } void range_initialize(const_iterator first, const_iterator last) { head.next = 0; __STL_TRY { _insert_after_range(&head, first, last); } __STL_UNWIND(clear()); } #endif /* __STL_MEMBER_TEMPLATES */ private: list_node_base head; // 这是链表头 public: slist() { head.next = 0; } slist(size_type n, const value_type& x) { fill_initialize(n, x); } slist(int n, const value_type& x) { fill_initialize(n, x); } slist(long n, const value_type& x) { fill_initialize(n, x); } explicit slist(size_type n) { fill_initialize(n, value_type()); } #ifdef __STL_MEMBER_TEMPLATES template <class InputIterator> slist(InputIterator first, InputIterator last) { range_initialize(first, last); } #else /* __STL_MEMBER_TEMPLATES */ slist(const_iterator first, const_iterator last) { range_initialize(first, last); } slist(const value_type* first, const value_type* last) { range_initialize(first, last); } #endif /* __STL_MEMBER_TEMPLATES */ slist(const slist& L) { range_initialize(L.begin(), L.end()); } slist& operator= (const slist& L); // 析构所有元素, 并释放内存 ~slist() { clear(); } public: iterator begin() { return iterator((list_node*)head.next); } const_iterator begin() const { return const_iterator((list_node*)head.next);} iterator end() { return iterator(0); } const_iterator end() const { return const_iterator(0); } size_type size() const { return __slist_size(head.next); } size_type max_size() const { return size_type(-1); } bool empty() const { return head.next == 0; } // 只需交换链表头数据就能实现交换^_^ void swap(slist& L) { list_node_base* tmp = head.next; head.next = L.head.next; L.head.next = tmp; } public: friend bool operator== __STL_NULL_TMPL_ARGS(const slist<T, Alloc>& L1, const slist<T, Alloc>& L2); public: // OK. 下面四个函数时间复杂度为O(1) // 对于插入操作只推荐push_front()其余操作个人感觉很慢 reference front() { return ((list_node*) head.next)->data; } const_reference front() const { return ((list_node*) head.next)->data; } void push_front(const value_type& x) { __slist_make_link(&head, create_node(x)); } void pop_front() { list_node* node = (list_node*) head.next; head.next = node->next; destroy_node(node); } // 获取指定结点的前驱结点 iterator previous(const_iterator pos) { return iterator((list_node*) __slist_previous(&head, pos.node)); } const_iterator previous(const_iterator pos) const { return const_iterator((list_node*) __slist_previous(&head, pos.node)); } private: // 在指定结点后插入值为x的元素, 分配内存 list_node* _insert_after(list_node_base* pos, const value_type& x) { return (list_node*) (__slist_make_link(pos, create_node(x))); } // 在指定结点后面插入n个值为x的元素 void _insert_after_fill(list_node_base* pos, size_type n, const value_type& x) { for (size_type i = 0; i < n; ++i) pos = __slist_make_link(pos, create_node(x)); } // TODO: 待分析 // 在pos后面插入[first, last)区间内的元素 #ifdef __STL_MEMBER_TEMPLATES template <class InIter> void _insert_after_range(list_node_base* pos, InIter first, InIter last) { while (first != last) { pos = __slist_make_link(pos, create_node(*first)); ++first; } } #else /* __STL_MEMBER_TEMPLATES */ void _insert_after_range(list_node_base* pos, const_iterator first, const_iterator last) { while (first != last) { pos = __slist_make_link(pos, create_node(*first)); ++first; } } void _insert_after_range(list_node_base* pos, const value_type* first, const value_type* last) { while (first != last) { pos = __slist_make_link(pos, create_node(*first)); ++first; } } #endif /* __STL_MEMBER_TEMPLATES */ // 擦除pos后面的结点 list_node_base* erase_after(list_node_base* pos) { list_node* next = (list_node*) (pos->next); list_node_base* next_next = next->next; pos->next = next_next; destroy_node(next); return next_next; } // 擦除(before_first, last_node)区间的结点 list_node_base* erase_after(list_node_base* before_first, list_node_base* last_node) { list_node* cur = (list_node*) (before_first->next); while (cur != last_node) { list_node* tmp = cur; cur = (list_node*) cur->next; destroy_node(tmp); } before_first->next = last_node; return last_node; } public: // 在pos后面插入值为x的结点 iterator insert_after(iterator pos, const value_type& x) { return iterator(_insert_after(pos.node, x)); } iterator insert_after(iterator pos) { return insert_after(pos, value_type()); } void insert_after(iterator pos, size_type n, const value_type& x) { _insert_after_fill(pos.node, n, x); } void insert_after(iterator pos, int n, const value_type& x) { _insert_after_fill(pos.node, (size_type) n, x); } void insert_after(iterator pos, long n, const value_type& x) { _insert_after_fill(pos.node, (size_type) n, x); } #ifdef __STL_MEMBER_TEMPLATES template <class InIter> void insert_after(iterator pos, InIter first, InIter last) { _insert_after_range(pos.node, first, last); } #else /* __STL_MEMBER_TEMPLATES */ void insert_after(iterator pos, const_iterator first, const_iterator last) { _insert_after_range(pos.node, first, last); } void insert_after(iterator pos, const value_type* first, const value_type* last) { _insert_after_range(pos.node, first, last); } #endif /* __STL_MEMBER_TEMPLATES */ // 在pos后面插入值为x的结点 iterator insert(iterator pos, const value_type& x) { return iterator(_insert_after(__slist_previous(&head, pos.node), x)); } iterator insert(iterator pos) { return iterator(_insert_after(__slist_previous(&head, pos.node), value_type())); } // 在pos前插入m个值为x的结点 void insert(iterator pos, size_type n, const value_type& x) { _insert_after_fill(__slist_previous(&head, pos.node), n, x); } void insert(iterator pos, int n, const value_type& x) { _insert_after_fill(__slist_previous(&head, pos.node), (size_type) n, x); } void insert(iterator pos, long n, const value_type& x) { _insert_after_fill(__slist_previous(&head, pos.node), (size_type) n, x); } #ifdef __STL_MEMBER_TEMPLATES template <class InIter> void insert(iterator pos, InIter first, InIter last) { _insert_after_range(__slist_previous(&head, pos.node), first, last); } #else /* __STL_MEMBER_TEMPLATES */ void insert(iterator pos, const_iterator first, const_iterator last) { _insert_after_range(__slist_previous(&head, pos.node), first, last); } void insert(iterator pos, const value_type* first, const value_type* last) { _insert_after_range(__slist_previous(&head, pos.node), first, last); } #endif /* __STL_MEMBER_TEMPLATES */ public: iterator erase_after(iterator pos) { return iterator((list_node*)erase_after(pos.node)); } iterator erase_after(iterator before_first, iterator last) { return iterator((list_node*)erase_after(before_first.node, last.node)); } iterator erase(iterator pos) { return (list_node*) erase_after(__slist_previous(&head, pos.node)); } iterator erase(iterator first, iterator last) { return (list_node*) erase_after(__slist_previous(&head, first.node), last.node); } // 详细剖析见后面实现部分 void resize(size_type new_size, const T& x); void resize(size_type new_size) { resize(new_size, T()); } void clear() { erase_after(&head, 0); } public: // splic操作可以参考<stl_list.h>的说明 // Moves the range [before_first + 1, before_last + 1) to *this, // inserting it immediately after pos. This is constant time. void splice_after(iterator pos, iterator before_first, iterator before_last) { if (before_first != before_last) __slist_splice_after(pos.node, before_first.node, before_last.node); } // Moves the element that follows prev to *this, inserting it immediately // after pos. This is constant time. void splice_after(iterator pos, iterator prev) { __slist_splice_after(pos.node, prev.node, prev.node->next); } // Linear in distance(begin(), pos), and linear in L.size(). void splice(iterator pos, slist& L) { if (L.head.next) __slist_splice_after(__slist_previous(&head, pos.node), &L.head, __slist_previous(&L.head, 0)); } // Linear in distance(begin(), pos), and in distance(L.begin(), i). void splice(iterator pos, slist& L, iterator i) { __slist_splice_after(__slist_previous(&head, pos.node), __slist_previous(&L.head, i.node), i.node); } // Linear in distance(begin(), pos), in distance(L.begin(), first), // and in distance(first, last). void splice(iterator pos, slist& L, iterator first, iterator last) { if (first != last) __slist_splice_after(__slist_previous(&head, pos.node), __slist_previous(&L.head, first.node), __slist_previous(first.node, last.node)); } public: // 这些接口可以参考<stl_list.h> void reverse() { if (head.next) head.next = __slist_reverse(head.next); } void remove(const T& val); void unique(); void merge(slist& L); void sort(); #ifdef __STL_MEMBER_TEMPLATES template <class Predicate> void remove_if(Predicate pred); template <class BinaryPredicate> void unique(BinaryPredicate pred); template <class StrictWeakOrdering> void merge(slist&, StrictWeakOrdering); template <class StrictWeakOrdering> void sort(StrictWeakOrdering comp); #endif /* __STL_MEMBER_TEMPLATES */ }; // 实现整个链表的赋值, 会析构原有的元素 template <class T, class Alloc> slist<T, Alloc>& slist<T,Alloc>::operator=(const slist<T, Alloc>& L) { if (&L != this) { list_node_base* p1 = &head; list_node* n1 = (list_node*) head.next; const list_node* n2 = (const list_node*) L.head.next; while (n1 && n2) { n1->data = n2->data; p1 = n1; n1 = (list_node*) n1->next; n2 = (const list_node*) n2->next; } if (n2 == 0) erase_after(p1, 0); else _insert_after_range(p1, const_iterator((list_node*)n2), const_iterator(0)); } return *this; } // 只有两个链表所有内容都相等才判定其等价 // 不过个人觉得只需要判断头结点指向的第一个结点就可以 // 大家可以讨论一下 template <class T, class Alloc> bool operator==(const slist<T, Alloc>& L1, const slist<T, Alloc>& L2) { typedef typename slist<T,Alloc>::list_node list_node; list_node* n1 = (list_node*) L1.head.next; list_node* n2 = (list_node*) L2.head.next; while (n1 && n2 && n1->data == n2->data) { n1 = (list_node*) n1->next; n2 = (list_node*) n2->next; } return n1 == 0 && n2 == 0; } // 字典序比较 template <class T, class Alloc> inline bool operator<(const slist<T, Alloc>& L1, const slist<T, Alloc>& L2) { return lexicographical_compare(L1.begin(), L1.end(), L2.begin(), L2.end()); } // 如果编译器支持模板函数特化优先级 // 那么将全局的swap实现为使用slist私有的swap以提高效率 #ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDER template <class T, class Alloc> inline void swap(slist<T, Alloc>& x, slist<T, Alloc>& y) { x.swap(y); } #endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */ //////////////////////////////////////////////////////////////////////////////// // 下面这些接口和list的行为一致, 只是算法有些不同, 请参考<stl_list.h> //////////////////////////////////////////////////////////////////////////////// template <class T, class Alloc> void slist<T, Alloc>::resize(size_type len, const T& x) { list_node_base* cur = &head; while (cur->next != 0 && len > 0) { --len; cur = cur->next; } if (cur->next) erase_after(cur, 0); else _insert_after_fill(cur, len, x); } template <class T, class Alloc> void slist<T,Alloc>::remove(const T& val) { list_node_base* cur = &head; while (cur && cur->next) { if (((list_node*) cur->next)->data == val) erase_after(cur); else cur = cur->next; } } template <class T, class Alloc> void slist<T,Alloc>::unique() { list_node_base* cur = head.next; if (cur) { while (cur->next) { if (((list_node*)cur)->data == ((list_node*)(cur->next))->data) erase_after(cur); else cur = cur->next; } } } template <class T, class Alloc> void slist<T,Alloc>::merge(slist<T,Alloc>& L) { list_node_base* n1 = &head; while (n1->next && L.head.next) { if (((list_node*) L.head.next)->data < ((list_node*) n1->next)->data) __slist_splice_after(n1, &L.head, L.head.next); n1 = n1->next; } if (L.head.next) { n1->next = L.head.next; L.head.next = 0; } } template <class T, class Alloc> void slist<T,Alloc>::sort() { if (head.next && head.next->next) { slist carry; slist counter[64]; int fill = 0; while (!empty()) { __slist_splice_after(&carry.head, &head, head.next); int i = 0; while (i < fill && !counter[i].empty()) { counter[i].merge(carry); carry.swap(counter[i]); ++i; } carry.swap(counter[i]); if (i == fill) ++fill; } for (int i = 1; i < fill; ++i) counter[i].merge(counter[i-1]); this->swap(counter[fill-1]); } } #ifdef __STL_MEMBER_TEMPLATES template <class T, class Alloc> template <class Predicate> void slist<T,Alloc>::remove_if(Predicate pred) { list_node_base* cur = &head; while (cur->next) { if (pred(((list_node*) cur->next)->data)) erase_after(cur); else cur = cur->next; } } template <class T, class Alloc> template <class BinaryPredicate> void slist<T,Alloc>::unique(BinaryPredicate pred) { list_node* cur = (list_node*) head.next; if (cur) { while (cur->next) { if (pred(((list_node*)cur)->data, ((list_node*)(cur->next))->data)) erase_after(cur); else cur = (list_node*) cur->next; } } } template <class T, class Alloc> template <class StrictWeakOrdering> void slist<T,Alloc>::merge(slist<T,Alloc>& L, StrictWeakOrdering comp) { list_node_base* n1 = &head; while (n1->next && L.head.next) { if (comp(((list_node*) L.head.next)->data, ((list_node*) n1->next)->data)) __slist_splice_after(n1, &L.head, L.head.next); n1 = n1->next; } if (L.head.next) { n1->next = L.head.next; L.head.next = 0; } } template <class T, class Alloc> template <class StrictWeakOrdering> void slist<T,Alloc>::sort(StrictWeakOrdering comp) { if (head.next && head.next->next) { slist carry; slist counter[64]; int fill = 0; while (!empty()) { __slist_splice_after(&carry.head, &head, head.next); int i = 0; while (i < fill && !counter[i].empty()) { counter[i].merge(carry, comp); carry.swap(counter[i]); ++i; } carry.swap(counter[i]); if (i == fill) ++fill; } for (int i = 1; i < fill; ++i) counter[i].merge(counter[i-1], comp); this->swap(counter[fill-1]); } } #endif /* __STL_MEMBER_TEMPLATES */ #if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32) #pragma reset woff 1174 #endif __STL_END_NAMESPACE #endif /* __SGI_STL_INTERNAL_SLIST_H */ // Local Variables: // mode:C++ // End:
时间: 2024-10-12 12:18:07