From 9fe41bb219af87601512edf756489977c1e29c86 Mon Sep 17 00:00:00 2001
From: Nur69 <60115902+Nur69@users.noreply.github.com>
Date: Sun, 19 Apr 2020 17:10:25 +0200
Subject: [PATCH] Topological Sort

directed graphs
---
 Sorts/TopologicalSort,js | 59 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 Sorts/TopologicalSort,js

diff --git a/Sorts/TopologicalSort,js b/Sorts/TopologicalSort,js
new file mode 100644
index 000000000..e76bfd666
--- /dev/null
+++ b/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());