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
|
package examples;
object maps {
import scala.collection.immutable._;
trait MapStruct[kt, vt] {
trait Map with Function1[kt, vt] {
def extend(key: kt, value: vt): Map;
def remove(key: kt): Map;
def domain: Stream[kt];
def range: Stream[vt];
}
type map <: Map;
val empty: map;
}
class AlgBinTree[kt <: Ordered[kt], vt <: AnyRef]() extends MapStruct[kt, vt] {
type map = AlgMap;
val empty: AlgMap = Empty();
private case class
Empty(),
Node(key: kt, value: vt, l: map, r: map) extends AlgMap {}
trait AlgMap extends Map {
def apply(key: kt): vt = this match {
case Empty() => null
case Node(k, v, l, r) =>
if (key < k) l.apply(key)
else if (key > k) r.apply(key)
else v
}
def extend(key: kt, value: vt): map = this match {
case Empty()=> Node(key, value, empty, empty)
case Node(k, v, l, r) =>
if (key < k) Node(k, v, l.extend(key, value), r)
else if (key > k) Node(k, v, l, r.extend(key, value))
else Node(k, value, l, r)
}
def remove(key: kt): map = this match {
case Empty()=> empty
case Node(k, v, l, r) =>
if (key < k) Node(k, v, l.remove(key), r)
else if (key > k) Node(k, v, l, r.remove(key))
else if (l == empty) r
else if (r == empty) l
else {
val midKey = r.domain.head;
Node(midKey, r.apply(midKey), l, r.remove(midKey))
}
}
def domain: Stream[kt] = this match {
case Empty()=> Stream.empty
case Node(k, v, l, r) => l.domain append Stream.cons(k, r.domain)
}
def range: Stream[vt] = this match {
case Empty()=> Stream.empty
case Node(k, v, l, r) => l.range append Stream.cons(v, r.range)
}
}
}
class OOBinTree[kt <: Ordered[kt], vt <: AnyRef]() extends MapStruct[kt, vt] {
type map = OOMap;
trait OOMap extends Map {
def apply(key: kt): vt;
def extend(key: kt, value: vt): map;
def remove(key: kt): map;
def domain: Stream[kt];
def range: Stream[vt];
}
val empty: OOMap = new OOMap {
def apply(key: kt): vt = null;
def extend(key: kt, value: vt) = new Node(key, value, empty, empty);
def remove(key: kt) = empty;
def domain: Stream[kt] = Stream.empty;
def range: Stream[vt] = Stream.empty;
}
private class Node(k: kt, v: vt, l: map, r: map) extends OOMap {
def apply(key: kt): vt =
if (key < k) l.apply(key)
else if (key > k) r.apply(key)
else v;
def extend(key: kt, value: vt): map =
if (key < k) new Node(k, v, l.extend(key, value), r)
else if (key > k) new Node(k, v, l, r.extend(key, value))
else new Node(k, value, l, r);
def remove(key: kt): map =
if (key < k) new Node(k, v, l.remove(key), r)
else if (key > k) new Node(k, v, l, r.remove(key))
else if (l == empty) r
else if (r == empty) l
else {
val midKey = r.domain.head;
new Node(midKey, r(midKey), l, r.remove(midKey))
}
def domain: Stream[kt] = l.domain append Stream.cons(k, r.domain);
def range: Stream[vt] = l.range append Stream.cons(v, r.range);
}
}
class MutBinTree[kt <: Ordered[kt], vt <: AnyRef]() extends MapStruct[kt, vt] {
type map = MutMap;
class MutMap(key: kt, value: vt) extends Map {
val k = key;
var v = value;
var l, r = empty;
def apply(key: kt): vt =
if (this == empty) null
else if (key < k) l.apply(key)
else if (key > k) r.apply(key)
else v;
def extend(key: kt, value: vt): map =
if (this == empty) new MutMap(key, value)
else {
if (key < k) l = l.extend(key, value)
else if (key > k) r = r.extend(key, value)
else v = value;
this
}
def remove(key: kt): map =
if (this == empty) this
else if (key < k) { l = l.remove(key) ; this }
else if (key > k) { r = r.remove(key) ; this }
else if (l == empty) r
else if (r == empty) l
else {
var mid = r;
while (!(mid.l == empty)) { mid = mid.l }
mid.r = r.remove(mid.k);
mid.l = l;
mid
}
def domain: Stream[kt] =
if (this == empty) Stream.empty;
else l.domain append Stream.cons(k, r.domain);
def range: Stream[vt] =
if (this == empty) Stream.empty;
else l.range append Stream.cons(v, r.range);
}
val empty = new MutMap(null, null);
}
class Date(y: Int, m: Int, d: Int) with Ordered[Date] {
def year = y;
def month = m;
def day = d;
def compareTo[b >: Date <% Ordered[b]](that: b): int = that match {
case other: Date =>
if ((year == other.year) &&
(month == other.month) &&
(day == other.day))
0
else if ((year < other.year) ||
(year == other.year && month < other.month) ||
(month == other.month && day < other.day))
-1
else
1
case _ =>
-(that compareTo this)
}
override def equals(that: Any): Boolean =
that.isInstanceOf[Date] && {
val o = that.asInstanceOf[Date];
day == o.day && month == o.month && year == o.year
}
}
def main(args: Array[String]) = {
val t = new OOBinTree[Date, String]();
()
}
}
|
