Update fragkos2021 and oliveira2020 references

Refresh the audited fragkos2021 tiny Gurobi certificate. Replace the oversized oliveira2020 tiny instance with the reproducible 8-job instance and proven reference, and correct derived metadata on its five large instances.

tasks/fragkos2021/gurobi_code.py

@@ -222,7 +222,7 @@ def main():
     # the latest captured incumbent (or the trivial stub if Gurobi found
     # nothing yet) — never a half-written or stale-dimension file.
     # ------------------------------------------------------------------
-    def _atomic_write_solution(path, x_vec, ub, elapsed_s, cuts):
+    def _atomic_write_solution(path, x_vec, ub, elapsed_s, cuts, solver_result=None):
         payload = {
             "objective_value": ub,
             "facility_locations": x_vec,
@@ -230,6 +230,8 @@ def main():
             "total_time_seconds": round(elapsed_s, 4),
             "cuts_added": cuts,
         }
+        if solver_result is not None:
+            payload.update(solver_result)
         dirn = _os.path.dirname(_os.path.abspath(path)) or "."
         fd, tmp = tempfile.mkstemp(prefix=_os.path.basename(path) + ".",
                                    suffix=".tmp", dir=dirn)
@@ -375,6 +377,11 @@ def main():
         best["ub"],
         total_time,
         best["cuts"],
+        {
+            "solver_status": model.Status,
+            "best_bound": model.ObjBound if model.SolCount > 0 else None,
+            "mip_gap": model.MIPGap if model.SolCount > 0 else None,
+        },
     )
 
     print(f"Objective value : {best['ub']:.4f}")

tasks/fragkos2021/gurobi_solution/tiny_solution.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:c91e0cb5852a8722f5b1908288c1850d8de596991186ebcfe66f005359954f5d
-size 315
+oid sha256:177ce5d1eff424729b2f82535e12444367becd22ac3b6bdd8ca24bbe598e1912
+size 422

tasks/oliveira2020/gurobi_code.py

@@ -73,7 +73,8 @@ def solve(instance_path, solution_path, time_limit):
 
     model = gp.Model("parallel_machine_weighted_tardiness")
     model.Params.Threads = 1
-    model.Params.TimeLimit = time_limit
+    if time_limit is not None:
+        model.Params.TimeLimit = time_limit
     model.Params.OutputFlag = 1
     model.Params.MIPFocus = 1
 
@@ -203,7 +204,15 @@ if __name__ == "__main__":
     parser.add_argument("--instance_path", required=True)
     parser.add_argument("--solution_path", required=True)
     parser.add_argument("--time_limit", type=int, default=3600)
+    parser.add_argument(
+        "--no-time-limit", action="store_true",
+        help="Run Gurobi without a solver time limit.",
+    )
     parser.add_argument("--log_path", default=None)
     arguments = parser.parse_args()
     install_gurobi_logger(arguments.log_path)
-    solve(arguments.instance_path, arguments.solution_path, arguments.time_limit)
+    solve(
+        arguments.instance_path,
+        arguments.solution_path,
+        None if arguments.no_time_limit else arguments.time_limit,
+    )

tasks/oliveira2020/gurobi_solution/tiny_solution.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:3cf2600bc1502e7034131d40c32e2d307b8301f23f1033848913bd1f35c5ab2b
-size 3121
+oid sha256:3a23a5c1c702bba90ffc41163148649bdc7a6ecb788e6b25edbbda27bbf09db2
+size 1535

tasks/oliveira2020/gurobi_solution_log/tiny_log.jsonl

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:23128e66b45f62a6b0ee0a9a79f628e0eff267abc138d96155bd7a25c2e638b1
-size 44
+oid sha256:efebef3b126d56b03db2679573f7e1a1d1248d75665143e67fa765a7a0c237da
+size 82

tasks/oliveira2020/instance/large_instance_1.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:4d25e0b24f22abff9d3e6ff4e9968a7a0bc9c8534d35791c7dd60edc73a280ef
-size 2071
+oid sha256:e6e0906cb22c0c5ac5c7c1df3ce74d4c880e40791c19e6b6264bb55dfff33c88
+size 2070

tasks/oliveira2020/instance/large_instance_2.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:e6c964ea5887257eef62b848436a056a797d6bf184411408d49d64a2f14173ad
-size 2085
+oid sha256:baf24c73ca304abd2f50a49266eb1a8ce3043b9e729b0db28605e76ad9e9aae6
+size 2083

tasks/oliveira2020/instance/large_instance_3.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:788e7e3107766e2b28d17357580b5aa9316a44e6e9e1bd2bd0d9d642f23076b1
-size 2079
+oid sha256:23786dc6afed78fda648e8d1956e047b668848119b71c93e4a5b0c9811b98021
+size 2077

tasks/oliveira2020/instance/large_instance_4.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:b723d2591dc927b6c056443bc04e296f629d7baba0517679f51ba548a1180323
-size 2075
+oid sha256:70ee6bb3b01b48631025a3d9e50026c8ca2e47a630a79b3171f651331b3f4254
+size 2073

tasks/oliveira2020/instance/large_instance_5.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:83bd9d965609d2fea3d062e73939788aae66ec27c83bebd38faa2af4d1a2b58a
-size 2073
+oid sha256:6ea77361f81eaabf6dc1aad12ccd2e534c5da5786eb10cc3984cb9e1c57b3471
+size 2071

tasks/oliveira2020/instance/tiny_instance.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:3c2e26750bf5562370399a5fc99bedcc619bdee6d504f69628df7dd52189fbe3
-size 2271
+oid sha256:af263e66ddd7afa088839bd3b566b4de16d0ec40634ca332ac279c02609189c1
+size 1134