Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I wish to retrieve values from a Java Key/Value pair (Map with one-to-many mapping) having only one corresponding key without looping over all the values in the Map and turning it into a O(n) complexity.
The Key/Value data structure would be like:
K1 –> V1, V2
K2 –> V1, V2, V3
K3 –> V1
K4 –>
K5 –> V4, V2
Would appreciate if anyone has any recommendations around the same or if this can be made better time-complexity wise.
In google’s guava there is a very nice BiMap class where you can look-up both keys and values (it is backed by two Maps).
http://code.google.com/p/guava-libraries/
EDITED: After clarification. I think my answer does not change much. Guava has also very nice MultiMap interface (and several implementations of it) which you can most likely use for your purpose.