Java 8 saw Map obtain the method computeIfAbsent, it saves a bunch of boilerplate, just like defaultdict. https://docs.oracle.com/javase/8/docs/api/java/util/M

Java 8 saw Map obtain the method computeIfAbsent, it saves a bunch of boilerplate, just like defaultdict. https://docs.oracle.com/javase/8/docs/api/java/util/Map.html#computeIfAbsent-K-java.util.function.Function- https://docs.oracle.com/javase/8/docs/api/java/util/Map.html...