realalg/heap_vector.cpp at master · jeyong/realalg · GitHub

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
#include<iostream>
#include <vector>

using namespace std;

template <typename T>
class Heap
{
private:
	vector<T> vec;
public:
	Heap() { };

	void Add(T n);
	void Remove();
	size_t Getsize();
	T GetParent(int index);
	int GetParentIndex(int index);

	T GetLeft(int index);
	int GetLeftIndex(int index);

	T GetRight(int index);
	int GetRightIndex(int index);
	void Siftup(int index);
	void Display();
};


template<typename T>
void Heap<T>::Add(T n)
{
	vec.push_back(n);
	Siftup(vec.size() - 1);
}

template<typename T>
T Heap<T>::GetParent(int index)
{
	if (index < 0 && index >= vec.size()) {
		return T();
	}
	int pi = GetParentIndex(index);
	return vec.at(pi);
}

template<typename T>
int Heap<T>::GetParentIndex(int index)
{
	return (index - 1) / 2;
}

template<typename T>
T Heap<T>::GetLeft(int index)
{

	if (index < 0 && index >= vec.size()) {
		return T();
	}

	int li = GetLeftIndex(index);
	if (li >= vec.size())
	{
		return T();
	}

	return vec.at(li);
}

template<typename T>
int Heap<T>::GetLeftIndex(int index)
{
	return 2 * index + 1;
}

template<typename T>
T Heap<T>::GetRight(int index)
{
	if (index < 0 && index >= vec.size())
	{
		return T();
	}

	int ri = GetRightIndex(index);
	if (ri >= vec.size())
	{
		return T();
	}
	return vec.at(ri);
}

template<typename T>
int Heap<T>::GetRightIndex(int index)
{
	return 2 * i + 2;
}

template<typename T>
void Heap<T>::Siftup(int index)
{
	if (index < 0 && index >= vec.size())
	{
		return;
	}

	auto p = GetParent(index);
	auto pi = GetParentIndex(index);
	if (pi >= vec.size())
	{
		return;
	}

	if (vec.at(index) > vec.at(pi))
	{
		auto temp = vec[pi];
		vec[pi] = vec[index];
		vec[index] = temp;

		Siftup(pi);
	}

}

template<typename T>
void Heap<T>::Display()
{
	for (auto e : vec)
	{
		cout << e <<": ";
	}
	cout << endl;
}

int main()
{
	Heap<int> h;
	for (auto i = 0; i < 10; i++)
	{
		h.Add(i+10);
	}
	h.Display();
	return 0;
}