-
Notifications
You must be signed in to change notification settings - Fork 0
/
AVL Tree Insertion.cpp
85 lines (65 loc) · 2.29 KB
/
AVL Tree Insertion.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
unordered_map<Node*, int> height;
class Solution{
public:
Node * leftrotate(Node * node){
Node * toreturn = node -> right;
node -> right = toreturn -> left;
toreturn -> left = node;
return toreturn;
}
Node * rightrotate(Node * node){
Node * toreturn = node -> left;
node -> left = toreturn -> right;
toreturn -> right = node;
return toreturn;
}
/*You are required to complete this method */
Node* insertToAVL(Node* node, int data)
{
if(node == nullptr){
Node * newnode = new Node(data);
height[newnode] = 1;
return newnode;
}
if(data < node -> data)
node -> left = insertToAVL(node -> left, data);
else
node -> right = insertToAVL(node -> right, data);
auto he = [&](Node * node) -> int {
if(node == nullptr)
return 0;
return height[node] = max(height[node -> left], height[node -> right]) + 1;
};
int bf = he(node -> left) - he(node -> right);
if(abs(bf) > 1){
if(bf < 0){
// right imbalance
if(data < (node -> right) -> data){
// right - left imbalance
node -> right = rightrotate(node -> right);
node = leftrotate(node);
}
else{
// right - right imbalance
node = leftrotate(node);
}
}
else{
// left imbalance
if(data < (node -> left) -> data){
// left - left imbalance
node = rightrotate(node);
}
else{
// left - right imbalance
node -> left = leftrotate(node -> left);
node = rightrotate(node);
}
}
he(node);
he(node -> left);
he(node -> right);
}
return node;
}
};