From deec2b4981bd7c2a2a84fa8775fd5ac3f6e987a4 Mon Sep 17 00:00:00 2001
From: Andrew Ekstedt <andrew.ekstedt@gmail.com>
Date: Thu, 11 Dec 2025 00:00:49 +0000
Subject: [PATCH] day 10 attempt with sympy

---
 day10/sol2.py | 70 +++++++++++++++++++++++++++++++++++----------------
 1 file changed, 49 insertions(+), 21 deletions(-)

diff --git a/day10/sol2.py b/day10/sol2.py
index 7d7095f..d886ce6 100644
--- a/day10/sol2.py
+++ b/day10/sol2.py
@@ -1,32 +1,60 @@
-import numpy, numpy.linalg
+import sympy
+import itertools
 def solve(input):
-    less = 0
-    greater = 0
+    part2 = 0
     for line in open(input):
         parts = line.split()[1:]
         idxs = [delist(p) for p in parts[:-1]]
         target = delist(parts[-1])
-        if len(idxs) != len(target) and 0:
-            if len(idxs) > len(target):
-                greater += 1
-            if len(idxs) < len(target):
-                less += 1
-            #print(line.strip())
-        else:
-            #assert len(idxs) == len(target)
-            N = len(target)
-            matrix = [[int(i in row) for i in range(N)] for row in idxs]
 
-            #print(matrix, target)
-            arr = numpy.array(matrix)
-            print(arr)
-            try:
-                print(target, numpy.linalg.lstsq(arr.T, target))
-            except numpy.linalg.LinAlgError as ex:
-                print(target, ex)
-    print(less, greater)
+        BTNS = len(idxs)
+        N = len(target)
+        matrix = [[int(i in row) for i in range(N)] for row in idxs]
+
+        #print(matrix, target)
+        M = sympy.Matrix(matrix + [target]).T
+        #print(repr(M))
+        S, pivots = M.rref()
+        if len(pivots) < BTNS:
+            # not solved
+            print(repr(S))
+            coords = []
+            limits = []
+            extra_rows = []
+            for p in range(BTNS):
+                if p not in pivots:
+                    print(p, M.col(p))
+                    row = [0]*(BTNS+1)
+                    row[p] = 1
+                    coords.append((M.rows, M.cols-1))
+                    extra_rows.append(row)
+                    limit = min(target[i] for i,x in enumerate(M.col(p)) if x)
+                    limits.append(limit)
+            M = M.col_join(sympy.Matrix(extra_rows))
+            print(repr(M), limits)
+            totals = []
+            for values in itertools.product(*[range(l+1) for l in limits]):
+                for c,v in zip(coords,values):
+                    M[c] = v
+                S, newpivot = M.rref()
+                presses = S.col(-1)
+                if all(int(x) >= 0 for x in presses):
+                    print(presses.T, flush=True)
+                    totals.append(sum(S.col(-1)))
+            if totals:
+                print("*", target, totals, min(totals))
+                part2 += min(totals)
+            else:
+                print("uhoh", target)
+        else:
+            presses = S.col(-1)
+            print("*", target, presses.T, sum(presses))
+            part2 += sum(presses)
+    print(part2)
+    #print(less, greater)
 
 def delist(s):
     return [int(x) for x in s.strip("{}()").split(',')]
 
+#solve("sample")
 solve("input")