...and nonempty. For 95%+ of problems, the .ans file is the "solution" to the testcase. If all .ans files in a given directory are the same, this is likely an error (for example, all testcases have the answer "IMPOSSIBLE").
For interactive problems, they're commonly left empty, which we should allow. Otherwise, I can't think of a reasonable usage where they are all nonempty and the same that cannot be done in another way. One way that I think covers most cases would be to use output_validator_flags to pass the group index to the output validator, and the output validator can then itself compute an arbitrary function {group index} -> {data}).
...and nonempty. For 95%+ of problems, the
.ansfile is the "solution" to the testcase. If all.ansfiles in a given directory are the same, this is likely an error (for example, all testcases have the answer "IMPOSSIBLE").For interactive problems, they're commonly left empty, which we should allow. Otherwise, I can't think of a reasonable usage where they are all nonempty and the same that cannot be done in another way. One way that I think covers most cases would be to use
output_validator_flagsto pass the group index to the output validator, and the output validator can then itself compute an arbitrary function {group index} -> {data}).