massive buy upgrade, sorting and bidding

util.lua

@@ -1,5 +1,11 @@
 Aux.util = {}
 
+Aux.util.LT = {}
+Aux.util.EQ = {}
+Aux.util.GT = {}
+
+local merge, copy_array
+
 function Aux.util.iter(array)
 	local with_index = ipairs(array)
 	return function()
@@ -93,4 +99,68 @@ function Aux.util.set_filter(set, p)
 		end
 	end
 	return filtered
+end
+
+function Aux.util.merge_sort(A, comp)
+	local n = getn(A)
+	local B = {}
+	
+	local width = 1
+	while width <= n do
+
+		for i=1, n, 2 * width do
+			merge(A, i, min(i + width, n), min(i + 2 * width - 1, n), B, comp)
+        end
+	  
+		copy_array(B, A, n)
+  
+		width = 2 * width
+    end
+end
+
+function merge(A, start1, start2, last, B, comp)
+	local i1 = start1
+	local i2 = start2
+
+	for i=start1,last do
+		if i1 < start2 and (i2 > last or comp(A[i1], A[i2]) == Aux.util.LT or comp(A[i1], A[i2]) == Aux.util.EQ) then
+			B[i] = A[i1]
+			i1 = i1 + 1
+		else
+			B[i] = A[i2]
+			i2 = i2 + 1
+		end
+	end
+end
+
+function copy_array(A, B, n)
+    for i=1,n do
+        B[i] = A[i]
+	end
+end
+
+function Aux.util.invert_order(ordering)
+	if ordering == Aux.util.LT then
+		return Aux.util.GT
+	elseif ordering == Aux.util.GT then
+		return Aux.util.LT
+	else
+		return Aux.util.EQ
+	end
+end
+
+function Aux.util.compare(a, b, nil_ordering)
+	if not a and b then
+		return nil_ordering
+	elseif a and not b then
+		return Aux.util.invert_order(nil_ordering)
+	elseif not a and not b then
+		return Aux.util.EQ
+	elseif a < b then
+		return Aux.util.LT
+	elseif a > b then
+		return Aux.util.GT
+	else
+		return Aux.util.EQ
+	end
 end