Add Neo4j day 2 homework

neo4j/homework.md

@@ -16,16 +16,70 @@
 
 ### Do, 1.
 
-```
+```cypher
 MATCH (n) RETURN n
 ```
 
 ### Do, 2.
 
-```
+```cypher
 MATCH (n) DETACH DELETE n
 ```
 
 ### Do, 3.
 
 Skipped.
+
+## Day 2
+
+### Find, 1.
+
+[Neo4j REST API Documentation](https://neo4j.com/docs/rest-docs/current/)
+
+### Find, 2.
+
+[Jung API Javadoc](http:https://jung.sourceforge.net/doc/api/index.html)
+
+### Find, 3.
+
+[Using Neo4j from Python](https://neo4j.com/developer/python/)
+
+### Do, 1.
+
+```groovy
+def actor(g, name) {
+ g.V.filter{it.name == name}.next()
+}
+
+Gremlin.defineStep('costars', [Vertex, Pipe], {
+ _().sideEffect{start = it}
+ .outE('ACTED_IN')
+ .inV
+ .inE('ACTED_IN')
+ .outV
+ .filter{!start.equals(it)}
+ .dedup
+})
+
+Gremlin.defineStep('path', [Vertex, Pipe], { target ->
+ _().costars
+ .loop(1){it.loops < 4 & !it.object.equals(target)}
+ .filter{it.equals(target)}
+ .path
+})
+
+def compare_distance(actor1, actor2, target) {
+ distance = {a, b -> (a.path(b).next().size() - 3) / 2}
+ actor1.name + ': ' + distance(actor1, target) + ', ' + actor2.name + ': ' + distance(actor2, target)
+}
+
+g = new Neo4jGraph('/Users/peferron/Downloads/neo4j-1.9.7/data/graph.db')
+bacon = actor(g, 'Kevin Bacon')
+elvis = actor(g, 'Elvis Presley')
+roddy = actor(g, 'Roddy McDowall')
+compare_distance(elvis, roddy, bacon)
+```
+
+### Do, 2 & 3.
+
+Skipped.