Merge pull request #6 from sirwez/master

Author: abranhe

DataStructures/Hashset/Hashset.lua

@@ -0,0 +1,94 @@
+local hashset = {}
+
+hashset.__index = hashset
+
+hashset.Node = {}
+hashset.Node.__index = hashset.Node
+
+function hashset.Node.create(key)
+    local s = {}
+    setmetatable(s, hashset.Node)
+
+    s.key = key
+    s.next = nil
+
+    return s
+end
+
+function hashset.create(hash)
+    local s = {}
+    setmetatable(s, hashset)
+
+    if hash == nil then
+        hash = function(x) return x end
+    end
+
+    s.s = {}
+    s.N = 0
+    s.hash = hash
+
+    return s
+end
+
+function hashset:add(key)
+    local h = self.hash(key)
+    local x = self.s[h]
+    local found = false
+    while x ~= nil do
+        if x.key == key then
+            found = true
+            break
+        end
+        x = x.next
+    end
+
+    if found == false then
+        local old = self.s[h]
+        self.s[h] = hashset.Node.create(key)
+        self.s[h].next = old
+        self.N = self.N + 1
+    end
+
+end
+
+function hashset:contains(key)
+    local h = self.hash(key)
+    local x = self.s[h]
+    while x ~= nil do
+        if x.key == key then
+            return true
+        end
+        x = x.next
+    end
+    return false
+end
+
+function hashset:size()
+    return self.N
+end
+
+function hashset:isEmpty()
+    return self.N == 0
+end
+
+function hashset:remove(key)
+    local h = self.hash(key)
+    local x = self.s[h]
+    local prev_x = nil
+    while x ~= nil do
+        if x.key == key then
+            if prev_x == nil then
+                self.s[h] = x.next
+            else
+                prev_x.next = x.next
+            end
+            self.N = self.N - 1
+        end
+        prev_x = x
+        x = x.next
+    end
+
+    return nil
+end
+
+return hashset

DataStructures/List/List.lua

@@ -0,0 +1,137 @@
+local list = {}
+
+list.ArrayList = {}
+list.ArrayList.__index = list.ArrayList
+
+function list.ArrayList.create()
+    local s = {}
+    setmetatable(s, list.ArrayList)
+
+    s.a = { nil }
+    s.aLen = 1
+    s.N = 0
+    return s
+end
+
+function list.ArrayList.createWith(a, aLen, N)
+    local s = {}
+    setmetatable(s, list.ArrayList)
+
+    s.a = a
+    s.aLen = aLen
+    s.N = N
+    return s
+end
+
+function list.create()
+    return list.ArrayList.create()
+end
+
+function list.createWith(a, aLen, N)
+    return list.ArrayList.createWith(a, aLen, N)
+end
+
+function list.ArrayList:makeCopy()
+    local temp = {}
+    for key,val in pairs(self.a) do
+        temp[key] = val
+    end
+    return list.ArrayList.createWith(temp, self.aLen, self.N)
+end
+
+function list.ArrayList:add(value)
+    self.a[self.N] = value
+    self.N = self.N + 1
+    if self.N == self.aLen then
+        self:resize(self.aLen * 2)
+    end
+end
+
+function list.ArrayList:set(index,value)
+    self.a[index] = value
+end
+
+function list.ArrayList:get(index)
+    local temp = self.a[index]
+    return temp
+end
+
+function list.ArrayList:removeAt(index)
+    if index == self.N-1 then
+        self.N = self.N - 1
+        return
+    end
+    for i = index+1,self.N-1 do
+        self.a[i-1]=self.a[i]
+    end
+    self.N = self.N - 1
+    if self.N == math.floor(self.aLen / 4) then
+        self:resize(math.floor(self.aLen / 2))
+    end
+
+end
+
+function list.ArrayList:indexOf(value)
+    if self.N == 0 then
+        return -1
+    end
+    for i=0,self.N-1 do
+        if self.a[i] == value then
+            return i
+        end
+    end
+    return -1
+end
+
+function list.ArrayList:remove(value)
+    local index = self:indexOf(value)
+    self:removeAt(index)
+end
+
+function list.ArrayList:resize(newSize)
+    local temp = {}
+    for i = 0,(newSize-1) do
+        temp[i] = self.a[i]
+    end
+
+    self.a = temp
+    self.aLen = newSize
+end
+
+function list.ArrayList:size()
+    return self.N
+end
+
+function list.ArrayList:isEmpty()
+    return self.N == 0
+end
+
+function list.ArrayList:enumerate()
+    local temp = {}
+    for i = 0,(self.N-1) do
+        temp[i] = self.a[i]
+    end
+    return temp
+end
+
+function list.ArrayList:isSortedAscendingly(comparator)
+    for i=0,(self:size()-2) do
+        if comparator(a:get(i), a:get(i+1)) > 0 then
+            return false
+        end
+
+    end
+    return true
+end
+
+function list.ArrayList:isSortedDescendingly(comparator)
+    for i=0,(self:size()-2) do
+        if comparator(a:get(i), a:get(i+1)) < 0 then
+            return false
+        end
+
+    end
+    return true
+end
+
+return list

DataStructures/Queue/Queue.lua

@@ -0,0 +1,153 @@
+local queue = {}
+
+queue.LinkedListQueue = {}
+queue.LinkedListQueue.__index = queue.LinkedListQueue
+
+queue.Node = {}
+queue.Node.__index = queue.Node
+
+function queue.Node.create(value)
+    local s = {}
+    setmetatable(s, queue.Node)
+
+    s.value = value
+    s.next = nil
+
+    return s
+end
+
+function queue.LinkedListQueue.create()
+    local s = {}
+    setmetatable(s, queue.LinkedListQueue)
+
+    s.first = nil
+    s.last = nil
+    s.N = 0
+
+    return s
+end
+
+function queue.create()
+    return queue.LinkedListQueue.create()
+end
+
+function queue.LinkedListQueue:enqueue(value)
+    local oldLast = self.last
+    self.last = queue.Node.create(value)
+    if oldLast ~= nil then
+        oldLast.next = self.last
+    end
+    if self.first == nil then
+        self.first = self.last
+    end
+    self.N = self.N + 1
+end
+
+function queue.LinkedListQueue:dequeue()
+    local oldFirst = self.first
+    if oldFirst == nil then
+        return nil
+    end
+    self.first = oldFirst.next
+    local value = oldFirst.value
+    if self.first == nil then
+        self.last = nil
+    end
+    self.N = self.N - 1
+    return value
+end
+
+function queue.LinkedListQueue:size()
+    return self.N
+end
+
+function queue.LinkedListQueue:isEmpty()
+    return self.N == 0
+end
+
+function queue.LinkedListQueue:enumerate()
+    local index = 0
+    local temp = {}
+    local x = self.first
+    while x ~= nil do
+        local value = x.value
+        temp[index] = value
+        index = index + 1
+        x = x.next
+    end
+
+    return temp
+
+end
+
+queue.ArrayQueue = {}
+queue.ArrayQueue.__index = queue.ArrayQueue
+
+function queue.ArrayQueue.create()
+    local s = {}
+    setmetatable(s, queue.ArrayQueue)
+
+    s.head = 0
+    s.tail = 0
+    s.a = { nil }
+    s.aLen = 0
+
+    return s
+end
+
+function queue.ArrayQueue:enqueue(value)
+    self.a[self.tail] = value
+    self.tail = self.tail + 1
+    if self.tail - self.head == self.aLen then
+        self:resize(self.aLen * 2)
+    end
+
+end
+
+function queue.ArrayQueue:size()
+    return self.tail - self.head
+end
+
+function queue.ArrayQueue:isEmpty()
+    return self.tail == self.head
+end
+
+function queue.ArrayQueue:dequeue(value)
+    if self.tail == self.head then
+        return nil
+    end
+
+    value = self.a[self.head]
+    self.head = self.head + 1
+    if self.tail - self.head == math.floor(self.aLen / 4) then
+        self:resize(math.floor(self.aLen / 2))
+    end
+
+    return value
+end
+
+function queue.ArrayQueue:resize(newSize)
+    local temp = {}
+    for i = 0,(newSize-1) do
+        if i < self.tail - self.head then
+            temp[i] = nil
+        else
+            temp[i] = self.a[i + self.head]
+        end
+    end
+
+    self.a = temp
+    self.aLen = newSize
+    self.tail = self.tail - self.head
+    self.head = 0
+end
+
+function queue.ArrayQueue:enumerate()
+    local temp = {}
+    for i = self.head,self.tail-1 do
+        temp[i - self.head] = self.a[i]
+    end
+    return temp
+end
+
+return queue