-
Notifications
You must be signed in to change notification settings - Fork 1
/
linkedStack.cpp
92 lines (81 loc) · 1.7 KB
/
linkedStack.cpp
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
// create on 2016-01-14
#include <iostream>
enum ErrorCode {
success,
underflow,
overflow
};
template <typename StackEntry>
struct Node {
StackEntry data;
Node *next;
Node(StackEntry val, Node *ptr = NULL): data(val), next(ptr) {}
};
template <typename StackEntry>
class MyStack {
public:
MyStack();
bool empty() const;
int size() const;
ErrorCode pop();
ErrorCode top(StackEntry& item) const;
ErrorCode push(const StackEntry& item);
void clear();
private:
Node<StackEntry>* pTop;
};
template <typename StackEntry>
MyStack<StackEntry>::MyStack() {
pTop = NULL;
}
template <typename StackEntry>
bool MyStack<StackEntry>::empty() const {
return pTop == NULL;
}
template <typename StackEntry>
int MyStack<StackEntry>::size() const {
Node<StackEntry> *ptr = pTop;
int count = 0;
while (ptr) {
++count;
ptr = ptr->next;
}
return count;
}
template<typename StackEntry>
ErrorCode MyStack<StackEntry>::pop() {
ErrorCode ans = success;
if (empty()) {
ans = underflow;
} else {
Node<StackEntry>* toDelete = pTop;
pTop = pTop->next;
delete toDelete;
}
return ans;
}
template<typename StackEntry>
ErrorCode MyStack<StackEntry>::top(StackEntry& item) const {
if (empty()) {
return underflow;
} else {
item = pTop->data;
return success;
}
}
template <typename StackEntry>
ErrorCode MyStack<StackEntry>::push(const StackEntry& item) {
Node<StackEntry> *newNode = new Node<StackEntry>(item);
newNode->next = pTop;
pTop = newNode;
return success;
}
template <typename StackEntry>
void MyStack<StackEntry>::clear() {
Node<StackEntry> *toDelete = NULL;
while (pTop) {
toDelete = pTop;
pTop = pTop->next;
delete toDelete;
}
}