Kakao Announces Results of Kakao Code Festival Online Qualifiers; 153 Finalists Confirmed

Kakao announced the results of the online qualifiers for the Kakao Code Festival, held on August 5. This event is the first developer event held under the name 'Kakao' following the merger, featuring a total of 6 problems with varying difficulty levels.

Finals Qualification Criteria and Results

A total of 153 participants were confirmed as finalists. The 71 participants who solved 4 or more problems advanced first, including 12 who solved all problems, 19 who solved 5, and 40 who solved 4. Among the 82 participants who solved 3 problems, the top 29 secured additional finals tickets based on the announced ranking criteria.

The scoring criteria are as follows:

• All problems have equal point values, and points are awarded only if all test cases are passed, with no partial credit.
• Ties are broken by the order of 'time to reach highest score + penalty', with smaller values ranked higher.
• The penalty adds 4 minutes per submission attempt before solving a problem.

Key Problem Solutions and Features

The 6 problems varied in difficulty and approach. 'Pedestrian Paradise' was a counting problem utilizing Dynamic Programming (DP), while 'Camping' required optimizing from an impossible O(n^3) solution to O(n^2) using prefix sum arrays for n=5,000. 'Mysterious Ruins Exploration' was a problem about finding the maximum common part of two trees, solvable using methods such as Minimum-cost flow or the Hungarian method.

Meanwhile, there was an error in the grading data during the competition, but the final rankings reflect results graded with corrected data that matches the problem descriptions.