Build and return a HashMap that sends strings to row indexes

Question

Build and return a HashMap that sends strings to row indexes such that the HashMap allows you to lookup the index of a row that contains a specified string value in column 'label'.

https://code.sololearn.com/cqjeFt1jI6Ah/#java

Can someone help me to figure out it?

Answer 1

https://code.sololearn.com/cq9N8SczyUJg/?ref=app

Answer 2

how about https://code.sololearn.com/c2N6p26FWLr4/#java?