fix bruteforce not checking every stock sorting, use sorted set for best results to skip duplicates, sort results by biggest trimmings; update and fix tests, add test for #68; update v1.1.1

Author: ModischFabrications

app/settings.py

@@ -2,7 +2,7 @@
 from pydantic_settings import BaseSettings
 
 # constant; used for git tags
-version = "v1.1.0"
+version = "v1.1.1"
 
 
 class SolverSettings(BaseSettings):

app/solver/solver.py

@@ -33,9 +33,9 @@ def solve(job: Job) -> Result:
 # slowest, but perfect solver; originally O(n!), now much faster (see Job.n_combinations())
 def _solve_bruteforce(job: Job) -> tuple[ResultEntry, ...]:
     minimal_trimmings = float('inf')
-    best_results = []
+    best_results: set[tuple[ResultEntry, ...]] = set()
 
-    required_orderings = distinct_permutations(job.iterate_required())
+    required_orderings = list(distinct_permutations(job.iterate_required()))
     for stock_ordering in distinct_permutations(job.iterate_stocks()):
         for required_ordering in required_orderings:
             result = _group_into_lengths(stock_ordering, required_ordering, job.cut_width)
@@ -45,12 +45,13 @@ def _solve_bruteforce(job: Job) -> tuple[ResultEntry, ...]:
             trimmings = sum(lt.trimming for lt in result)
             if trimmings < minimal_trimmings:
                 minimal_trimmings = trimmings
-                best_results = [result]
+                best_results = set()
+                best_results.add(sort_entries(result))
             elif trimmings == minimal_trimmings:
-                best_results.append(result)
+                best_results.add(sort_entries(result))
 
     assert best_results, "No valid solution found"
-    return sort_entries(find_best_solution(best_results))
+    return find_best_solution(best_results)
 
 
 def _group_into_lengths(stocks: tuple[NS, ...], sizes: tuple[NS, ...], cut_width: int) \

app/solver/utils.py

@@ -20,13 +20,12 @@ def calc_trimming(stock_length: int, lengths: Collection[NS], cut_width: int) ->
     return trimmings
 
 
-def find_best_solution(solutions: Sequence):
+def find_best_solution(solutions: set[tuple[ResultEntry, ...]]):
     if len(solutions) <= 0:
         raise ValueError("no solution to search")
 
     # TODO evaluate which one aligns with user expectations best (see #68)
-    # always sort for determinism!
-    return sorted(solutions, reverse=True)[0]
+    return sorted(solutions, key=lambda x: max(x), reverse=True)[0]
 
 
 def create_result_entry(stock: NS, cuts: list[NS], cut_width: int) -> ResultEntry:
@@ -37,7 +36,7 @@ def create_result_entry(stock: NS, cuts: list[NS], cut_width: int) -> ResultEntr
     )
 
 
-def sort_entries(result_entries: list[ResultEntry]) -> tuple[ResultEntry, ...]:
+def sort_entries(result_entries: Sequence[ResultEntry]) -> tuple[ResultEntry, ...]:
     if len(result_entries) <= 0:
         raise ValueError("no entries to sort")
     return tuple(sorted(result_entries))

tests/res/out/testresult_s.json

@@ -21,7 +21,7 @@
     ]
   },
   "solver_type": "bruteforce",
-  "time_us": 1868,
+  "time_us": 1683,
   "layout": [
     {
       "stock": {
@@ -34,8 +34,8 @@
           "name": "Part1"
         },
         {
-          "length": 200,
-          "name": "Part2"
+          "length": 500,
+          "name": "Part1"
         },
         {
           "length": 200,
@@ -46,7 +46,7 @@
           "name": "Part2"
         }
       ],
-      "trimming": 392
+      "trimming": 92
     },
     {
       "stock": {
@@ -55,15 +55,15 @@
       },
       "cuts": [
         {
-          "length": 500,
-          "name": "Part1"
+          "length": 200,
+          "name": "Part2"
         },
         {
           "length": 200,
           "name": "Part2"
         }
       ],
-      "trimming": 796
+      "trimming": 1096
     }
   ]
 }

tests/solver/test_large.py

@@ -15,6 +15,8 @@ def test_m(solver):
 
     solved = solver(testjob_m)
 
+    assert sum(lt.trimming for lt in solved) == 855
+
     # I don't care about ordering here
     assert sorted([r.cuts for r in solved]) == sorted([
         (NS(length=500), NS(length=300), NS(length=100)),
@@ -27,7 +29,7 @@ def test_m(solver):
 # close to the max for bruteforce!
 @pytest.mark.parametrize("solver", [_solve_bruteforce, _solve_FFD, _solve_gapfill])
 def test_m_multi(solver):
-    testjob_m = Job(stocks=(INS(length=900), INS(length=500, quantity=2), INS(length=100, quantity=1)),
+    testjob_m = Job(stocks=(INS(length=900, quantity=3), INS(length=500, quantity=2), INS(length=100, quantity=1)),
                     cut_width=10,
                     required=(
                         QNS(length=500, quantity=4), QNS(length=300, quantity=3),
@@ -41,10 +43,11 @@ def test_m_multi(solver):
     perfect_trimmings = 520
     perfect_result = (
         ResultEntry(stock=NS(length=500), cuts=(NS(length=500),), trimming=0),
-        ResultEntry(stock=NS(length=500), cuts=(NS(length=300),), trimming=190),
+        ResultEntry(stock=NS(length=500), cuts=(NS(length=300), NS(length=100)), trimming=80),
         ResultEntry(stock=NS(length=900), cuts=(NS(length=500), NS(length=300)), trimming=80),
         ResultEntry(stock=NS(length=900), cuts=(NS(length=500), NS(length=300)), trimming=80),
-        ResultEntry(stock=NS(length=900), cuts=(NS(length=500), NS(length=100), NS(length=100)), trimming=170))
+        ResultEntry(stock=NS(length=900), cuts=(NS(length=500), NS(length=100)), trimming=280)
+    )
 
     if solver == _solve_bruteforce:
         assert trimmings == perfect_trimmings

tests/solver/test_special.py

@@ -123,3 +123,19 @@ def test_close_stocks(solver):
         ResultEntry(stock=NS(length=100), cuts=(NS(length=100),), trimming=0),
         ResultEntry(stock=NS(length=100), cuts=(NS(length=100),), trimming=0),
         ResultEntry(stock=NS(length=100), cuts=(NS(length=100),), trimming=0))
+
+
+# @pytest.mark.xfail(reason="bug #68")
+def test_solution_priorities():
+    testjob_equal = Job(stocks=(INS(length=2400, quantity=1), (INS(length=6000, quantity=1))), cut_width=20,
+                        required=(QNS(length=1820, quantity=1), QNS(length=666, quantity=3)))
+    # other solvers have singular result, so no priorities
+    solved = _solve_bruteforce(testjob_equal)
+
+    # assert sum(lt.trimming for lt in solved) == 2102
+
+    assert solved == (
+        ResultEntry(stock=NS(length=6000),
+                    cuts=(NS(length=1820), NS(length=666), NS(length=666), NS(length=666)),
+                    trimming=2102),
+    )