flow like the river

VISUALIZACION/node_modules/ngraph.graph/examples/findConnectedComponents.js

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+/**
+ * This examples shows how to find all connected components of a graph.
+ * 
+ * Created in response to https://github.com/anvaka/ngraph.graph/issues/18
+ */
+module.exports = function findConnectedComponents(graph) {
+  var nodeIdToComponentId = new Map();
+
+  var connectedComponents = [];
+  var lastComponentId = 0;
+
+  graph.forEachNode(function(node) {
+    if (nodeIdToComponentId.has(node.id)) {
+      // we already seen this cluster. Ignore it.
+      return;
+    }
+
+    // We found a new connected component:
+    nodeIdToComponentId.set(node.id, lastComponentId);
+    var currentComponent = [node.id];
+    connectedComponents.push(currentComponent);
+
+    // Let's find what other nodes belong to this component
+    dfs(graph, node.id, otherNode => {
+      let componentId = nodeIdToComponentId.get(otherNode.id);
+      if (componentId !== undefined && componentId === lastComponentId) {
+        // this is possible when we have a loop. Just ignore the node.
+        return false;
+      } else if (componentId !== undefined) {
+        throw new Error('Reached a component from another component. DFS is broken?');
+      }
+
+      currentComponent.push(otherNode.id);
+      nodeIdToComponentId.set(otherNode.id, lastComponentId);
+
+      return true; // let's visit neighbors
+    });
+
+    lastComponentId += 1;
+  });
+
+  return connectedComponents;
+};
+
+function dfs(graph, startFromNodeId, visitor) {
+  graph.forEachLinkedNode(startFromNodeId, function(otherNode) {
+    if (visitor(otherNode)) dfs(graph, otherNode.id, visitor);
+  });
+}