Determine if a number is a 'happy number'. A happy number eventually reaches 1 when replaced by the sum of the squares of its digits, repeating the process until it does.

You're given a list of jobs with start times, end times, and profits. Find the maximum profit you can obtain by scheduling a subset of jobs that don't overlap.

You are given a list of events with start times, end times, and values. Determine the maximum total value you can obtain by attending at most 'k' events, without any overlapping events.