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
|
package scala.tools.nsc.util
import BitSet._
abstract class BitSet {
protected def nwords: Int
protected def word(idx: Int): Long
protected def updateWord(idx: Int, w: Long): BitSet
def + (elem: Int): BitSet = {
require(elem >= 0)
if (contains(elem)) this
else {
val idx = elem >> LogWL
updateWord(idx, word(idx) | (1L << elem))
}
}
def - (elem: Int): BitSet = {
require(elem >= 0)
if (contains(elem)) {
val idx = elem >> LogWL
updateWord(idx, word(idx) & ~(1L << elem))
} else this
}
def | (other: BitSet): BitSet = {
val len = this.nwords max other.nwords
val words = new Array[Long](len)
for (idx <- 0 until len)
words(idx) = this.word(idx) | other.word(idx)
fromArray(words)
}
def & (other: BitSet): BitSet = {
val len = this.nwords min other.nwords
val words = new Array[Long](len)
for (idx <- 0 until len)
words(idx) = this.word(idx) & other.word(idx)
fromArray(words)
}
def &~ (other: BitSet): BitSet = {
val len = this.nwords
val words = new Array[Long](len)
for (idx <- 0 until len)
words(idx) = this.word(idx) & ~other.word(idx)
fromArray(words)
}
def ^ (other: BitSet): BitSet = {
val len = this.nwords max other.nwords
val words = new Array[Long](len)
for (idx <- 0 until len)
words(idx) = this.word(idx) ^ other.word(idx)
fromArray(words)
}
def contains(elem: Int): Boolean =
0 <= elem && (word(elem >> LogWL) & (1L << elem)) != 0
def subSet(other: BitSet): Boolean =
(0 until nwords) forall (idx => (this.word(idx) & ~ other.word(idx)) == 0L)
override def equals(other: Any) = other match {
case that: BitSet =>
(0 until (this.nwords max that.nwords)) forall (idx => this.word(idx) == that.word(idx))
case _ =>
false
}
override def hashCode: Int = {
var h = hashSeed
for (idx <- 0 until nwords) {
val w = word(idx)
h = (h * 41 + (w >>> 32).toInt) * 41 + w.toInt
}
h
}
def addString(sb: StringBuilder, start: String, sep: String, end: String) {
sb append start
var pre = ""
for (i <- 0 until nwords * WordLength)
if (contains(i)) {
sb append pre append i
pre = sep
}
sb append end
}
def mkString(start: String, sep: String, end: String) = {
val sb = new StringBuilder
addString(sb, start, sep, end)
sb.toString
}
override def toString = mkString("BitSet(", ", ", ")")
}
object BitSet {
private final val WordLength = 64
private final val LogWL = 6
private val hashSeed = "BitSet".hashCode
val empty: BitSet = new BitSet1(0L)
def apply(elems: Int*) = (empty /: elems) (_ + _)
def fromArray(elems: Array[Long]) = {
val len = elems.length
if (len == 0) empty
else if (len == 1) new BitSet1(elems(0))
else if (len == 2) new BitSet2(elems(0), elems(1))
else new BitSetN(elems)
}
private def updateArray(elems: Array[Long], idx: Int, w: Long): BitSet = {
var len = elems.length
while (len > 0 && (elems(len - 1) == 0L || w == 0L && idx == len - 1)) len -= 1
var newlen = len
if (idx >= newlen && w != 0L) newlen = idx + 1
val newelems = new Array[Long](newlen)
Array.copy(elems, 0, newelems, 0, len)
if (idx < newlen) newelems(idx) = w
else assert(w == 0L)
fromArray(newelems)
}
class BitSet1(val elems: Long) extends BitSet {
protected def nwords = 1
protected def word(idx: Int) = if (idx == 0) elems else 0L
protected def updateWord(idx: Int, w: Long): BitSet =
if (idx == 0) new BitSet1(w)
else if (idx == 1) new BitSet2(elems, w)
else updateArray(Array(elems), idx, w)
}
class BitSet2(val elems0: Long, elems1: Long) extends BitSet {
protected def nwords = 2
protected def word(idx: Int) = if (idx == 0) elems0 else if (idx == 1) elems1 else 0L
protected def updateWord(idx: Int, w: Long): BitSet =
if (idx == 0) new BitSet2(w, elems1)
else if (idx == 1) new BitSet2(elems0, w)
else updateArray(Array(elems0, elems1), idx, w)
}
class BitSetN(val elems: Array[Long]) extends BitSet {
protected def nwords = elems.length
protected def word(idx: Int) = if (idx < nwords) elems(idx) else 0L
protected def updateWord(idx: Int, w: Long): BitSet = updateArray(elems, idx, w)
}
}
|