Add solution for exercise 12

Author: mmarx

solutions/12-betweenness.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+
+import argparse
+from networkit import *
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description=("Compute Betweenness for a given graph")
+    )
+    parser.add_argument("input", help="path to input graph")
+    parser.add_argument("dict", help="path to input dict")
+    args = parser.parse_args()
+
+    graph = None
+    labels = {}
+
+    with open(args.dict, "r") as dictfile:
+        for line in dictfile:
+            vertex, label = line.split(",", 1)
+            labels[int(vertex)] = label.strip()[1:-1]
+
+    graph = readGraph(args.input, Format.METIS)
+    betweenness = centrality.Betweenness(graph)
+    ranking = betweenness.run().ranking()
+
+    for vertex, rank in ranking[:20]:
+        print("{}. {}".format(rank, labels[int(vertex + 1)]))