notes on fix.

018/Path.java

@@ -4,6 +4,20 @@ import java.io.FileReader;
 import java.io.BufferedReader;
 import java.io.FileNotFoundException;
 
+/*
+ *
+To fix:
+don't use the sum of the subtree,
+use the EXPECTATION:
+
+E(subtree) = E(level1)+E(level2)+...
+
+E(level1) = one possibility
+E(level2) = (1/2)(outcome1) + (1/2)(outcome2)
+E(level3) = (1/4)(outcome1) + (1/4)(outcome2) + (1/4)(outcome3) + (1/4)(outcome4)
+
+*/
+
 public class Path {
 
 	public static final String FILE = "tri_test2.txt";