added two last functions of tools.ml

outfile

@@ -0,0 +1,21 @@
+% This is a graph.
+
+n 0.0 1.0
+n 1.0 1.0
+n 2.0 1.0
+n 3.0 1.0
+n 4.0 1.0
+n 5.0 1.0
+
+e 0 2 8
+e 0 3 10
+e 0 1 7
+e 2 4 12
+e 3 4 5
+e 3 2 2
+e 3 1 11
+e 1 4 1
+e 1 5 21
+e 4 5 14
+
+% End of graph