blob: e95a0acbd136d84fe8919c9e02199f0062ecf208 (
plain)
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
|
/* list.cpp
* Date: 2021-11-20
* Author: Aryadev Chavali
*/
#include <cstdio>
#include <iostream>
#include <cstdlib>
template <typename T>
struct List
{
T value;
struct List<T> *next;
~List()
{
if (next == nullptr)
return;
delete next;
}
};
template <typename T>
List<T> *append(List<T> *lst, T value)
{
List<T> *node;
if (lst == nullptr)
{
node = new List<T>;
node->value = value;
node->next = nullptr;
return node;
}
for (node = lst; node->next != nullptr; node = node->next)
continue;
node->next = new List<T>;
node->next->value = value;
node->next->next = nullptr;
return lst;
}
/** Reverse a list
*/
template <typename T>
List<T> *reverse(List<T> *lst, List<T> *prev = nullptr)
{
auto next = lst->next;
lst->next = prev;
if (next == nullptr)
return lst;
return reverse(next, lst);
}
template <typename T, typename U>
void map(List<T> *lst, U (*f)(T))
{
if (!lst)
return;
lst->value = f(lst->value);
map(lst->next, f);
}
template <typename T>
std::ostream& operator<<(std::ostream& ostream, const List<T> *lst)
{
if (!lst)
return ostream;
ostream << "|" << lst->value << lst->next;
return ostream;
}
int main(void)
{
auto lst = append<int>(nullptr, 1);
for (int i = 2; i < 10; ++i)
lst = append(lst, i);
std::cout << lst << std::endl;
lst = reverse(lst);
std::cout << lst << std::endl;
map<int, int>(lst = reverse(lst), [](int x){ return x * 2; });
std::cout << lst << std::endl;
delete lst;
return 0;
}
|