Initial data commit

Task/Sorting-algorithms-Pancake-sort/Lua/sorting-algorithms-pancake-sort.lua

@@ -0,0 +1,65 @@
+-- Initialisation
+math.randomseed(os.time())
+numList = {step = 0, sorted = 0}
+
+-- Create list of n random values
+function numList:build (n)
+    self.values = {}
+    for i = 1, n do self.values[i] = math.random(-100, 100) end
+end
+
+-- Return boolean indicating whether the list is in order
+function numList:isSorted ()
+    for i = 2, #self.values do
+        if self.values[i] < self.values[i - 1] then return false end
+    end
+    print("Finished!")
+    return true
+end
+
+-- Display list of numbers on one line
+function numList:show ()
+    if self.step == 0 then
+        io.write("Initial state:\t")
+    else
+        io.write("After step " .. self.step .. ":\t")
+    end
+    for _, v in ipairs(self.values) do io.write(v .. " ") end
+    print()
+end
+
+-- Reverse n values from the left
+function numList:reverse (n)
+    local flipped = {}
+    for i, v in ipairs(self.values) do
+        if i > n then
+            flipped[i] = v
+        else
+            flipped[i] = self.values[n + 1 - i]
+        end
+    end
+    self.values = flipped
+end
+
+-- Perform one flip of a pancake sort
+function numList:pancake ()
+    local maxPos = 1
+    for i = 1, #self.values - self.sorted do
+        if self.values[i] > self.values[maxPos] then maxPos = i end
+    end
+    if maxPos == 1 then
+        numList:reverse(#self.values - self.sorted)
+        self.sorted = self.sorted + 1
+    else
+        numList:reverse(maxPos)
+    end
+    self.step = self.step + 1
+end
+
+-- Main procedure
+numList:build(10)
+numList:show()
+repeat
+    numList:pancake()
+    numList:show()
+until numList:isSorted()