events is a list of [team, points] pairs recorded during a season (points may be negative
for penalties). Total each team's points and return the leaderboard as a list of strings
"team: total", ordered from highest total to lowest. Teams with equal totals are ordered
alphabetically by name.
Examples
Input: events = [["red", 3], ["blue", 5], ["red", 4], ["green", 7]]
Output: ["green: 7", "red: 7", "blue: 5"]
Input: events = [["x", 1]]
Output: ["x: 1"]
Constraints
0 <= len(events) <= 1000; team names are lowercase words.
Goals
- Accumulate totals per team from a stream of events
- Sort by score descending with an alphabetical tie-break
- Format results as strings