From bd9292ccd46e6435b0aeecaf2f8ece34c5de4a9c Mon Sep 17 00:00:00 2001
From: Justin Lin <wancat@wancat.cc>
Date: Sat, 2 May 2026 16:19:50 +1000
Subject: [PATCH] try lru cache

---
 picky/picky.py | 54 ++++++++++++++++++++++++++------------------------
 1 file changed, 28 insertions(+), 26 deletions(-)

diff --git a/picky/picky.py b/picky/picky.py
index 10e9561..27fb1d2 100644
--- a/picky/picky.py
+++ b/picky/picky.py
@@ -1,3 +1,4 @@
+import functools
 import math
 import sys
 
@@ -10,17 +11,18 @@ def inputs():
 
 n, wet_c, dry_c = inputs()
 
-costs = [[(math.inf, -1)] * (dry_c + 1) for _ in range(wet_c + 1)]
-costs[0][0] = (0, -1)
+cost_map = {}
+cost_map[(0, 0)] = (0, -1)
 
 bundles = []
 for i in range(n):
     wet, dry, cost = inputs()
     bundles.append((wet, dry, cost))
     if wet <= wet_c and dry <= dry_c:
-        costs[wet][dry] = (cost, i)
+        cost_map[(wet, dry)] = (cost, i)
 
 
+@functools.lru_cache
 def get_cost(w, d) -> float:
     if w == 0 and d == 0:
         return 0
@@ -28,48 +30,48 @@ def get_cost(w, d) -> float:
     if w < 0 or d < 0:
         return math.inf
 
-    if costs[w][d][1] != -1:
-        print("reusing: ", w, d)
-        return costs[w][d][0]
-
-    print(w, d)
+    if (w, d) in cost_map:
+        # print("reusing: ", w, d)
+        return cost_map[(w, d)][0]
 
+    # print(w, d)
+    cost_map[(w, d)] = (math.inf, -1)
     for i in range(len(bundles)):
         wet, dry, cost = bundles[i]
         new_cost = get_cost(w - wet, d - dry) + cost
-        if costs[w][d][0] > new_cost:
-            costs[w][d] = (new_cost, i)
-    return costs[w][d][0]
+        if cost_map[(w, d)][0] > new_cost:
+            cost_map[(w, d)] = (new_cost, i)
+    return cost_map[(w, d)][0]
 
 
-def bottom_up() -> float:
-    for w in range(wet_c + 1):
-        for d in range(dry_c + 1):
-            for i in range(len(bundles)):
-                wet, dry, cost = bundles[i]
-                if wet > w or dry > d:
-                    continue
-                new_cost = costs[w - wet][d - dry][0] + cost
-                if costs[w][d][0] > new_cost:
-                    costs[w][d] = (new_cost, i)
+# def bottom_up() -> float:
+#     for w in range(wet_c + 1):
+#         for d in range(dry_c + 1):
+#             for i in range(len(bundles)):
+#                 wet, dry, cost = bundles[i]
+#                 if wet > w or dry > d:
+#                     continue
+#                 new_cost = costs[w - wet][d - dry][0] + cost
+#                 if costs[w][d][0] > new_cost:
+#                     costs[w][d] = (new_cost, i)
 
-    return costs[wet_c][dry_c][0]
+#     return costs[wet_c][dry_c][0]
 
 
 def backtrack(w, d) -> list[int]:
     counter = [0] * n
-    b = costs[w][d][1]
+    b = cost_map[(w, d)][1]
     while b != -1:
         counter[b] += 1
         wet, dry, _ = bundles[b]
         w -= wet
         d -= dry
-        b = costs[w][d][1]
+        b = cost_map[(w, d)][1]
     return counter
 
 
-# c = get_cost(wet_c, dry_c)
-c = bottom_up()
+c = get_cost(wet_c, dry_c)
+# c = bottom_up()
 # print(costs)
 if math.isinf(c):
     print(-1)