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kelvinlauKLkelvinlauKL
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Merge pull request kodecocodes#251 from goingreen/master
Migrate treap to swift 3
2 parents 61a12a2 + 4f5565d commit 7686092

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12 files changed

+375
-1342
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12 files changed

+375
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lines changed

‎.travis.yml

+1
Original file line numberDiff line numberDiff line change
@@ -39,3 +39,4 @@ script:
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# - xcodebuild test -project ./Single-Source\ Shortest\ Paths\ \(Weighted\)/SSSP.xcodeproj -scheme SSSPTests
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- xcodebuild test -project ./Stack/Tests/Tests.xcodeproj -scheme Tests
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# - xcodebuild test -project ./Topological\ Sort/Tests/Tests.xcodeproj -scheme Tests
42+
- xcodebuild test -project ./Treap/Treap/Treap.xcodeproj -scheme Tests

‎Treap/Treap.swift

+126-127
Original file line numberDiff line numberDiff line change
@@ -25,146 +25,145 @@ THE SOFTWARE.*/
2525
import Foundation
2626

2727
public indirect enum Treap<Key: Comparable, Element> {
28-
case Empty
29-
case Node(key: Key, val: Element, p: Int, left: Treap, right: Treap)
30-
31-
public init() {
32-
self = .Empty
33-
}
34-
35-
internal func get(key: Key) -> Element? {
36-
switch self {
37-
case .Empty:
38-
return nil
39-
case let .Node(treeKey, val, _, _, _) where treeKey == key:
40-
return val
41-
case let .Node(treeKey, _, _, left, _) where key < treeKey:
42-
return left.get(key)
43-
case let .Node(treeKey, _, _, _, right) where key > treeKey:
44-
return right.get(key)
45-
default:
46-
return nil
47-
}
28+
case empty
29+
case node(key: Key, val: Element, p: Int, left: Treap, right: Treap)
30+
31+
public init() {
32+
self = .empty
33+
}
34+
35+
internal func get(_ key: Key) -> Element? {
36+
switch self {
37+
case .empty:
38+
return nil
39+
case let .node(treeKey, val, _, _, _) where treeKey == key:
40+
return val
41+
case let .node(treeKey, _, _, left, _) where key < treeKey:
42+
return left.get(key)
43+
case let .node(treeKey, _, _, _, right) where key > treeKey:
44+
return right.get(key)
45+
default:
46+
return nil
4847
}
49-
50-
public func contains(key: Key) -> Bool {
51-
switch self {
52-
case .Empty:
53-
return false
54-
case let .Node(treeKey, _, _, _, _) where treeKey == key:
55-
return true
56-
case let .Node(treeKey, _, _, left, _) where key < treeKey:
57-
return left.contains(key)
58-
case let .Node(treeKey, _, _, _, right) where key > treeKey:
59-
return right.contains(key)
60-
default:
61-
return false
62-
}
48+
}
49+
50+
public func contains(_ key: Key) -> Bool {
51+
switch self {
52+
case .empty:
53+
return false
54+
case let .node(treeKey, _, _, _, _) where treeKey == key:
55+
return true
56+
case let .node(treeKey, _, _, left, _) where key < treeKey:
57+
return left.contains(key)
58+
case let .node(treeKey, _, _, _, right) where key > treeKey:
59+
return right.contains(key)
60+
default:
61+
return false
6362
}
64-
65-
public var depth: Int {
66-
get {
67-
switch self {
68-
case .Empty:
69-
return 0
70-
case let .Node(_, _, _, left, .Empty):
71-
return 1 + left.depth
72-
case let .Node(_, _, _, .Empty, right):
73-
return 1 + right.depth
74-
case let .Node(_, _, _, left, right):
75-
let leftDepth = left.depth
76-
let rightDepth = right.depth
77-
return 1 + max(leftDepth, rightDepth)
78-
}
79-
80-
}
63+
}
64+
65+
public var depth: Int {
66+
get {
67+
switch self {
68+
case .empty:
69+
return 0
70+
case let .node(_, _, _, left, .empty):
71+
return 1 + left.depth
72+
case let .node(_, _, _, .empty, right):
73+
return 1 + right.depth
74+
case let .node(_, _, _, left, right):
75+
let leftDepth = left.depth
76+
let rightDepth = right.depth
77+
return 1 + leftDepth > rightDepth ? leftDepth : rightDepth
78+
}
79+
8180
}
82-
83-
public var count: Int {
84-
get {
85-
return Treap.countHelper(self)
86-
}
81+
}
82+
83+
public var count: Int {
84+
get {
85+
return Treap.countHelper(self)
8786
}
88-
89-
private static func countHelper(treap: Treap<Key, Element>) -> Int {
90-
if case let .Node(_, _, _, left, right) = treap {
91-
return countHelper(left) + 1 + countHelper(right)
92-
}
93-
94-
return 0
87+
}
88+
89+
fileprivate static func countHelper(_ treap: Treap<Key, Element>) -> Int {
90+
if case let .node(_, _, _, left, right) = treap {
91+
return countHelper(left) + 1 + countHelper(right)
9592
}
93+
94+
return 0
95+
}
9696
}
9797

98-
internal func leftRotate<Key: Comparable, Element>(tree: Treap<Key, Element>) -> Treap<Key, Element> {
99-
if case let .Node(key, val, p, .Node(leftKey, leftVal, leftP, leftLeft, leftRight), right) = tree {
100-
return .Node(key: leftKey, val: leftVal, p: leftP, left: leftLeft,
101-
right: Treap.Node(key: key, val: val, p: p, left: leftRight, right: right))
102-
} else {
103-
return .Empty
104-
}
98+
internal func leftRotate<Key: Comparable, Element>(_ tree: Treap<Key, Element>) -> Treap<Key, Element> {
99+
if case let .node(key, val, p, .node(leftKey, leftVal, leftP, leftLeft, leftRight), right) = tree {
100+
return .node(key: leftKey, val: leftVal, p: leftP, left: leftLeft,
101+
right: Treap.node(key: key, val: val, p: p, left: leftRight, right: right))
102+
} else {
103+
return .empty
104+
}
105105
}
106106

107-
internal func rightRotate<Key: Comparable, Element>(tree: Treap<Key, Element>) -> Treap<Key, Element> {
108-
if case let .Node(key, val, p, left, .Node(rightKey, rightVal, rightP, rightLeft, rightRight)) = tree {
109-
return .Node(key: rightKey, val: rightVal, p: rightP,
110-
left: Treap.Node(key: key, val: val, p: p, left: left, right: rightLeft), right: rightRight)
111-
} else {
112-
return .Empty
113-
}
107+
internal func rightRotate<Key: Comparable, Element>(_ tree: Treap<Key, Element>) -> Treap<Key, Element> {
108+
if case let .node(key, val, p, left, .node(rightKey, rightVal, rightP, rightLeft, rightRight)) = tree {
109+
return .node(key: rightKey, val: rightVal, p: rightP,
110+
left: Treap.node(key: key, val: val, p: p, left: left, right: rightLeft), right: rightRight)
111+
} else {
112+
return .empty
113+
}
114114
}
115115

116116
public extension Treap {
117-
internal func set(key: Key, val: Element, p: Int = Int(arc4random())) -> Treap {
118-
switch self {
119-
case .Empty:
120-
return .Node(key: key, val: val, p: p, left: .Empty, right: .Empty)
121-
case let .Node(nodeKey, nodeVal, nodeP, left, right) where key != nodeKey:
122-
return insertAndBalance(nodeKey, nodeVal, nodeP, left, right, key, val, p)
123-
case let .Node(nodeKey, _, nodeP, left, right) where key == nodeKey:
124-
return .Node(key: key, val: val, p: nodeP, left: left, right: right)
125-
default: // should never happen
126-
return .Empty
127-
}
128-
117+
internal func set(key: Key, val: Element, p: Int = Int(arc4random())) -> Treap {
118+
switch self {
119+
case .empty:
120+
return .node(key: key, val: val, p: p, left: .empty, right: .empty)
121+
case let .node(nodeKey, nodeVal, nodeP, left, right) where key != nodeKey:
122+
return insertAndBalance(nodeKey, nodeVal, nodeP, left, right, key, val, p)
123+
case let .node(nodeKey, _, nodeP, left, right) where key == nodeKey:
124+
return .node(key: key, val: val, p: nodeP, left: left, right: right)
125+
default: // should never happen
126+
return .empty
129127
}
130-
131-
private func insertAndBalance(nodeKey: Key, _ nodeVal: Element, _ nodeP: Int, _ left: Treap,
132-
_ right: Treap, _ key: Key, _ val: Element, _ p: Int) -> Treap {
133-
let newChild: Treap<Key, Element>
134-
let newNode: Treap<Key, Element>
135-
let rotate: (Treap) -> Treap
136-
if key < nodeKey {
137-
newChild = left.set(key, val: val, p: p)
138-
newNode = .Node(key: nodeKey, val: nodeVal, p: nodeP, left: newChild, right: right)
139-
rotate = leftRotate
140-
} else if key > nodeKey {
141-
newChild = right.set(key, val: val, p: p)
142-
newNode = .Node(key: nodeKey, val: nodeVal, p: nodeP, left: left, right: newChild)
143-
rotate = rightRotate
144-
} else {
145-
// It should be impossible to reach here
146-
newChild = .Empty
147-
newNode = .Empty
148-
return newNode
149-
}
150-
151-
if case let .Node(_, _, newChildP, _, _) = newChild where newChildP < nodeP {
152-
return rotate(newNode)
153-
} else {
154-
return newNode
155-
}
128+
}
129+
130+
fileprivate func insertAndBalance(_ nodeKey: Key, _ nodeVal: Element, _ nodeP: Int, _ left: Treap,
131+
_ right: Treap, _ key: Key, _ val: Element, _ p: Int) -> Treap {
132+
let newChild: Treap<Key, Element>
133+
let newNode: Treap<Key, Element>
134+
let rotate: (Treap) -> Treap
135+
if key < nodeKey {
136+
newChild = left.set(key: key, val: val, p: p)
137+
newNode = .node(key: nodeKey, val: nodeVal, p: nodeP, left: newChild, right: right)
138+
rotate = leftRotate
139+
} else if key > nodeKey {
140+
newChild = right.set(key: key, val: val, p: p)
141+
newNode = .node(key: nodeKey, val: nodeVal, p: nodeP, left: left, right: newChild)
142+
rotate = rightRotate
143+
} else {
144+
// It should be impossible to reach here
145+
newChild = .empty
146+
newNode = .empty
147+
return newNode
156148
}
157-
158-
internal func delete(key: Key) throws -> Treap {
159-
switch self {
160-
case .Empty:
161-
throw NSError(domain: "com.wta.treap.errorDomain", code: -1, userInfo: nil)
162-
case let .Node(nodeKey, val, p, left, right) where key < nodeKey:
163-
return try Treap.Node(key: nodeKey, val: val, p: p, left: left.delete(key), right: right)
164-
case let .Node(nodeKey, val, p, left, right) where key > nodeKey:
165-
return try Treap.Node(key: nodeKey, val: val, p: p, left: left, right: right.delete(key))
166-
case let .Node(_, _, _, left, right):
167-
return merge(left, right: right)
168-
}
149+
150+
if case let .node(_, _, newChildP, _, _) = newChild , newChildP < nodeP {
151+
return rotate(newNode)
152+
} else {
153+
return newNode
154+
}
155+
}
156+
157+
internal func delete(key: Key) throws -> Treap {
158+
switch self {
159+
case .empty:
160+
throw NSError(domain: "com.wta.treap.errorDomain", code: -1, userInfo: nil)
161+
case let .node(nodeKey, val, p, left, right) where key < nodeKey:
162+
return try Treap.node(key: nodeKey, val: val, p: p, left: left.delete(key: key), right: right)
163+
case let .node(nodeKey, val, p, left, right) where key > nodeKey:
164+
return try Treap.node(key: nodeKey, val: val, p: p, left: left, right: right.delete(key: key))
165+
case let .node(_, _, _, left, right):
166+
return merge(left, right: right)
169167
}
168+
}
170169
}

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