Initial data commit

Task/Priority-queue/Stata/priority-queue.stata

@@ -0,0 +1,102 @@
+mata
+	struct Node {
+		real scalar time
+		transmorphic data
+		}
+	class Heap {
+		public:
+		struct Node rowvector nodes
+		real scalar len
+		real scalar size
+		real scalar minHeap
+		void new()
+		void push()
+		void siftup()
+		void siftdown()
+		struct Node scalar pop()
+		real scalar empty()
+		real scalar compare()
+		}
+	real scalar Heap::compare(a,b) {
+		struct Node scalar left, right
+		left = nodes[a]
+		right = nodes[b]
+		return(minHeap ? left.time<right.time : left.time>right.time)
+		}
+	void Heap::new()  {
+		len = 0
+		size = 4
+		nodes = Node(1,size)
+		minHeap = 1 // defaults to min heap
+		}
+	real scalar Heap::empty() {
+		return(len==0)
+		}
+	void Heap::siftdown(real scalar index) {
+		parent = index
+		while (parent*2 <= len) {
+			child = parent*2
+			if (child+1 <= len ? compare(child+1,child) : 0) {
+				child++
+				}
+			if (compare(child,parent)) {
+				nodes[(child,parent)] = nodes[(parent,child)]
+				parent = child
+				} else break
+			}
+		}
+	void Heap::siftup(real scalar index) {
+		child = index
+		while(child>1) {
+			parent = floor(child/2)
+			if (compare(parent,child)) {
+				break
+				}
+			nodes[(child,parent)] = nodes[(parent,child)]
+			temp = child
+			child = parent
+			parent = temp
+			}
+		}
+	void Heap::push (real scalar time, transmorphic data) {
+		if (len + 1 >= size) {
+			nodes = (nodes, nodes)
+			size = size*2
+			}
+		len++
+		nodes[len].time = time
+		nodes[len].data = data
+		siftup(len)
+		}
+	struct Node scalar Heap::pop () {
+		if (len==0) {
+			_error(3000,"empty heap")
+			}
+		len--
+		struct Node scalar newnode
+		newnode.time = nodes[1].time
+		newnode.data = nodes[1].data
+		if (len>0) {
+			nodes[1] = nodes[len+1]
+			siftdown(1)
+			}
+		return(newnode)
+		}
+	void testHeap(real scalar minHeap) {
+		class Heap scalar h
+		struct Node scalar node
+		h = Heap()
+		h.minHeap = minHeap
+		h.push(3, "Clear drains")
+		h.push(4, "Feed cat")
+		h.push(5, "Make tea")
+		h.push(1, "Solve RC tasks")
+		h.push(2, "Tax return")
+		while (!h.empty()) {
+			node = h.pop()
+			printf("%f -> %s\n", node.time, node.data)
+			}
+		}
+	testHeap(1)
+	testHeap(0)
+end