Topological Sort

directed graphs

Sorts/TopologicalSort,js

@@ -0,0 +1,59 @@
+function TopologicalSorter() {
+ var graph = {},
+ isVisitedNode,
+ finishTimeCount,
+ finishingTimeList,
+ nextNode;
+
+ this.addOrder = function (nodeA, nodeB) {
+ nodeA = String(nodeA);
+ nodeB = String(nodeB);
+ graph[nodeA] = graph[nodeA] || [];
+ graph[nodeA].push(nodeB);
+ }
+
+ this.sortAndGetOrderedItems = function () {
+ isVisitedNode = Object.create(null);
+ finishTimeCount = 0;
+ finishingTimeList = [];
+
+ for (var node in graph) {
+ if (graph.hasOwnProperty(node) && !isVisitedNode[node]) {
+ dfsTraverse(node);
+ }
+ }
+
+ finishingTimeList.sort(function (item1, item2) {
+ return item1.finishTime > item2.finishTime ? -1 : 1;
+ });
+
+ return finishingTimeList.map(function (value) { return value.node })
+ }
+
+ function dfsTraverse(node) {
+ isVisitedNode[node] = true;
+ if (graph[node]) {
+ for (var i = 0; i < graph[node].length; i++) {
+ nextNode = graph[node][i];
+ if (isVisitedNode[nextNode]) continue;
+ dfsTraverse(nextNode);
+ }
+ }
+
+ finishingTimeList.push({
+ node: node,
+ finishTime: ++finishTimeCount
+ });
+ }
+}
+
+
+/* TEST */
+var topoSorter = new TopologicalSorter();
+topoSorter.addOrder(5, 2);
+topoSorter.addOrder(5, 0);
+topoSorter.addOrder(4, 0);
+topoSorter.addOrder(4, 1);
+topoSorter.addOrder(2, 3);
+topoSorter.addOrder(3, 1);
+console.log(topoSorter.sortAndGetOrderedItems());