Squash commit

utilities/graphTopoSort.js

@@ -0,0 +1,35 @@
+function graphTopoSort(numberNodes, edges) {
+    const nodes = new Map();
+    const order = [];
+    const queue = [];
+    for (let i = 0; i < numberNodes; i++) {
+        nodes.set(i, { in: 0, out: new Set() });
+    }
+
+    edges.forEach(edge => {
+        const [node_id, pre_id] = edge;
+        nodes.get(node_id).in += 1;
+        nodes.get(pre_id).out.add(node_id);
+    });
+
+    for (let [node_id, value] of nodes.entries()) {
+        if (value.in === 0) {
+            queue.push(node_id);
+        }
+    }
+
+    while (queue.length) {
+        const node_id = queue.shift();
+        for (let outgoing_id of nodes.get(node_id).out) {
+            nodes.get(outgoing_id).in -= 1;
+            if (nodes.get(outgoing_id).in === 0) {
+                queue.push(outgoing_id);
+            }
+        }
+        order.push(node_id);
+    }
+
+    return order.length == numberNodes ? order : [];
+}
+
+console.log(graphTopoSort(3, [[0, 1], [0, 2]]))