misc: restructure contents

experimental/utilities/javascript/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]]));