If for a challenge problem I have submitted 2 solution on gets lets say 0.71 points and the other solution get 0 .64 point.
When contest gets over ans suppose a case arises that my new score of first solution will become less than the 2nd one (which previously has less score). Then which point will I be awarded?
As mentioned there, only 5 test files are used for testing. When the contest gets over, all the 15 files will be used to finalize the score and that score will be used for the rankings.
The solution which has final score high will be taken under evaluation.
The latest submission (AC) is accounted for testing on the remaining 10 files.