└── Implementation_of_heaps.c++


/Implementation_of_heaps.c++:
--------------------------------------------------------------------------------
 1 | #include <iostream>
 2 | #include <cstdlib>
 3 | #include <vector>
 4 | #include <iterator>
 5 | using namespace std; class BHeap {
 6 | private:
 7 | vector <int> heap; int l(int parent); int r(int parent); int par(int child);
 8 | void heapifyup(int index); void heapifydown(int index); public:
 9 | BHeap() {}
10 | void Insert(int element); void DeleteMin();
11 | int ExtractMin(); void showHeap(); int Size();
12 | };
13 | 
14 | int main() {
15 |  
16 | BHeap h; while (1) {
17 | cout<<"1.Insert Element"<<endl; cout<<"2.Delete Minimum Element"<<endl; cout<<"3.Extract Minimum Element"<<endl; cout<<"4.Show Heap"<<endl; cout<<"5.Exit"<<endl;
18 | int c, e;
19 | cout<<"Enter your choice: "; cin>>c;
20 | switch(c) { case 1:
21 | cout<<"Enter the element to be inserted: "; cin>>e;
22 | h.Insert(e); break;
23 | case 2: h.DeleteMin();
24 | break; case 3:
25 | if (h.ExtractMin() == -1) { cout<<"Heap is Empty"<<endl;
26 | }
27 | else
28 | cout<<"Minimum Element: "<<h.ExtractMin()<<endl; break;
29 | case 4:
30 | cout<<"Displaying elements of Hwap: "; h.showHeap();
31 | break; case 5:
32 | exit(1); default:
33 | cout<<"Enter Correct Choice"<<endl;
34 | }
35 | }
36 | return 0;
37 | }
38 | int BHeap::Size() { return heap.size();
39 | }
40 | void BHeap::Insert(int ele) { heap.push_back(ele);
41 | 
42 | heapifyup(heap.size() -1);
43 |  
44 | }
45 | void BHeap::DeleteMin() { if (heap.size() == 0) {
46 | cout<<"Heap is Empty"<<endl; return;
47 | }
48 | heap[0] = heap.at(heap.size() - 1); heap.pop_back(); heapifydown(0);
49 | cout<<"Element Deleted"<<endl;
50 | }
51 | int BHeap::ExtractMin() { if (heap.size() == 0) {
52 | return -1;
53 | }
54 | else
55 | return heap.front();
56 | }
57 | void BHeap::showHeap() {
58 | vector <int>::iterator pos = heap.begin(); cout<<"Heap --> ";
59 | while (pos != heap.end()) { cout<<*pos<<" "; pos++;
60 | }
61 | cout<<endl;
62 | }
63 | int BHeap::l(int parent) { int l = 2 * parent + 1;
64 | if (l < heap.size()) return l;
65 | else
66 | return -1;
67 | }
68 | int BHeap::r(int parent) { int r = 2 * parent + 2;
69 | if (r < heap.size()) return r;
70 | else
71 | return -1;
72 | }
73 | int BHeap::par(int child) { int p = (child - 1)/2;
74 | 
75 | if (child == 0)
76 |  
77 | return -1; else
78 | return p;
79 | }
80 | void BHeap::heapifyup(int in) {
81 | if (in >= 0 && par(in) >= 0 && heap[par(in)] > heap[in]) { int temp = heap[in];
82 | heap[in] = heap[par(in)]; heap[par(in)] = temp; heapifyup(par(in));
83 | }
84 | }
85 | void BHeap::heapifydown(int in) { int child = l(in);
86 | int child1 = r(in);
87 | if (child >= 0 && child1 >= 0 && heap[child] > heap[child1]) { child = child1;
88 | }
89 | if (child > 0 && heap[in] > heap[child]) { int t = heap[in];
90 | heap[in] = heap[child]; heap[child] = t; heapifydown(child);
91 | }
92 | }
93 | 


--------------------------------------------------------------------------------