1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
#ifndef LIST__H__
#define LIST__H__
template<class T> struct list_node
{
list_node* next;
T data;
list_node(T d, list_node* n = 0) : next(n), data(d) { }
~list_node() { }
};
template<class T> class list_iterator;
template<class T> class const_list_iterator;
template<class T> class list
{
public:
typedef list_node<T> node;
typedef list_iterator<T> iter;
typedef const_list_iterator<T> const_iter;
friend class iter;
friend class const_iter;
list()
: head(0), tail(0), cnt(0)
{
}
list(const list&);
~list()
{
empty();
}
unsigned count() const
{
return cnt;
}
void empty()
{
while(head) {
node* next = head->next;
delete head;
head = next;
}
tail = 0;
cnt = 0;
}
bool append(T data)
{
node* n = new node(data);
if(tail)
tail->next = n;
else
head = n;
tail = n;
++cnt;
return true;
}
bool prepend(T data)
{
head = new node(data, head);
if(!tail)
tail = head;
++cnt;
return true;
}
bool remove(iter&);
private:
node* head;
node* tail;
unsigned cnt;
};
template<class T> class const_list_iterator
{
friend class list<T>;
private:
inline void go_next()
{
prev = curr;
if(curr)
curr = curr->next;
}
public:
const_list_iterator(const list<T>& l)
: lst(l), prev(0), curr(l.head)
{
}
void operator++()
{
go_next();
}
void operator++(int)
{
go_next();
}
T operator*() const
{
return curr->data;
}
bool operator!() const
{
return curr == 0;
}
operator bool() const
{
return !operator!();
}
private:
const list<T>& lst;
const list<T>::node* prev;
const list<T>::node* curr;
};
template<class T>
list<T>::list(const list<T>& that)
: head(0), tail(0), cnt(0)
{
for(const_iter i = that; i; ++i)
append(*i);
}
template<class T> class list_iterator
{
friend class list<T>;
private:
inline void go_next()
{
prev = curr;
if(curr)
curr = curr->next;
}
public:
list_iterator(list<T>& l)
: lst(l), prev(0), curr(l.head)
{
}
void operator++()
{
go_next();
}
void operator++(int)
{
go_next();
}
T operator*() const
{
return curr->data;
}
T& operator*()
{
return curr->data;
}
bool operator!() const
{
return curr == 0;
}
operator bool() const
{
return !operator!();
}
private:
list<T>& lst;
list<T>::node* prev;
list<T>::node* curr;
};
template<class T>
bool list<T>::remove(list<T>::iter& iter)
{
if(this != &iter.lst)
return false;
if(!iter.curr)
return false;
if(iter.prev) {
iter.prev->next = iter.curr->next;
if(iter.curr == tail)
tail = iter.prev;
delete iter.curr;
iter.curr = iter.prev->next;
}
else {
head = iter.curr->next;
if(!head)
tail = 0;
delete iter.curr;
iter.curr = head;
}
--cnt;
return true;
}
#endif // LIST__H__
|
