Optimize memory consumption to avoid StackOverflowError

[PSSF23]

Using only the first two classes of the cifar10 datasets, when I try to run the following command:

./bin/spdt --model-path ./cifar_0_1 --class-labels 0,1 --training-data cifar10_0_1 --test-data cifar10_0_1.t

Such error messages appeared:

Exception in thread "main" java.lang.StackOverflowError
	at java.util.regex.Pattern$Curly.match(Pattern.java:4248)
	at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672)
	at java.util.regex.Pattern$BmpCharProperty.match(Pattern.java:3812)
	at java.util.regex.Pattern$GroupHead.match(Pattern.java:4672)
	at java.util.regex.Pattern$Loop.match(Pattern.java:4799)
	at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731)
	at java.util.regex.Pattern$GroupTail.match(Pattern.java:4731)
	at java.util.regex.Pattern$Curly.match2(Pattern.java:4325)
	at java.util.regex.Pattern$Curly.match(Pattern.java:4252)
	at java.util.regex.Pattern$Curly.match0(Pattern.java:4286)
	at java.util.regex.Pattern$Curly.match(Pattern.java:4248)
	at java.util.regex.Pattern$Ques.match(Pattern.java:4196)
	......

The overall message is even too long to fit here, but the gist is that poor memory management led to such an issue. I know that with python my computer can handle the whole cifar10 dataset with ease, so better memory management should be able to resolve the problem.