Repository navigation
Expand file tree
/
Copy pathinterval-tree.js
More file actions
202 lines (185 loc) · 4.99 KB
/
Copy pathinterval-tree.js
File metadata and controls
202 lines (185 loc) · 4.99 KB
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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
(function (exports) {
'use strict';
function Node(start, end, left, right) {
this.interval = [start, end];
this.max = -Infinity;
this.parentNode = null;
this.left = left;
this.right = right;
}
function IntervalTree() {
this.root = null;
}
function addNode(node, side, interval) {
var child = new Node(interval[0], interval[1]);
child.parentNode = node;
node[side] = child;
if (node.max < interval[1]) {
while (child) {
if (child.max < interval[1]) {
child.max = interval[1];
}
child = child.parentNode;
}
}
}
function addHelper(node, interval) {
if (node.interval[0] > interval[0]) {
if (node.left) {
addHelper(node.left, interval);
} else {
addNode(node, 'left', interval);
}
} else {
if (node.right) {
addHelper(node.right, interval);
} else {
addNode(node, 'right', interval);
}
}
}
IntervalTree.prototype.add = function (interval) {
if (!this.root) {
this.root = new Node(interval[0], interval[1]);
return;
}
addHelper(this.root, interval);
};
function contains(point, node) {
if (!node) {
return false;
}
if (node.interval[0] <= point && node.interval[1] >= point) {
return true;
}
var result = false, temp;
['left', 'right'].forEach(function (key) {
temp = node[key];
if (temp) {
if (temp.max > point) {
result = result || contains(point, temp);
}
}
});
return result;
}
IntervalTree.prototype.contains = function (point) {
return contains(point, this.root);
};
function intersectsHelper(interval, node) {
if (!node) {
return false;
}
if (intersects(node.interval, interval)) {
return true;
}
var result = false, temp;
['left', 'right'].forEach(function (side) {
temp = node[side];
if (temp && temp.max >= interval[0]) {
result = result || intersectsHelper(interval, temp);
}
});
return result;
}
function intersects(a, b) {
return (a[0] <= b[0] && a[1] >= b[0]) || (a[0] <= b[1] && a[1] >= b[1]) ||
(b[0] <= a[0] && b[1] >= a[0]) || (b[0] <= a[1] && b[1] >= a[1]);
}
IntervalTree.prototype.intersects = function (interval) {
return intersectsHelper(interval, this.root);
};
function heightHelper(node) {
if (!node) {
return 0;
}
return 1 + Math.max(heightHelper(node.left), heightHelper(node.right));
}
IntervalTree.prototype.height = function () {
return heightHelper(this.root);
};
IntervalTree.prototype.findMax = function (node) {
var stack = [node],
current, max = -Infinity, maxNode;
while (stack.length) {
current = stack.pop();
if (current.left) {
stack.push(current.left);
}
if (current.right) {
stack.push(current.right);
}
if (current.interval[1] > max) {
max = current.interval[1];
maxNode = current;
}
}
return maxNode;
};
// adjust the max value
IntervalTree.prototype._removeHelper = function (interval, node) {
if (!node) {
return;
}
if (node.interval[0] === interval[0] &&
node.interval[1] === interval[1]) {
// When left and right children exists
if (node.left && node.right) {
var replacement = node.left;
while (replacement.left) {
replacement = replacement.left;
}
var temp = replacement.interval;
replacement.interval = node.interval;
node.interval = temp;
this._removeHelper(replacement.interval, node);
} else {
// When only left or right child exists
var side = 'left';
if (node.right) {
side = 'right';
}
var parentNode = node.parentNode;
if (parentNode) {
if (parentNode.left === node) {
parentNode.left = node[side];
} else {
parentNode.right = node[side];
}
if (node[side]) {
node[side].parentNode = parentNode;
}
} else {
this.root = node[side];
// last node removed
if (this.root) {
this.root.parentNode = null;
}
}
}
// Adjust the max value
var p = node.parentNode;
if (p) {
var maxNode = this.findMax(p),
max = maxNode.interval[1];
while (maxNode) {
if (maxNode.max === node.interval[1]) {
maxNode.max = max;
maxNode = maxNode.parentNode;
} else {
maxNode = false;
}
}
}
} else {
// could be optimized
this._removeHelper(interval, node.left);
this._removeHelper(interval, node.right);
}
};
IntervalTree.prototype.remove = function (interval) {
return this._removeHelper(interval, this.root);
};
exports.Node = Node;
exports.IntervalTree = IntervalTree;
}(typeof exports === 'undefined' ? window : exports));