From 74b7c774d6a0d5ef5a959b418a126b14802d0ede Mon Sep 17 00:00:00 2001
From: Andrew Ekstedt <andrew.ekstedt@gmail.com>
Date: Wed, 17 Dec 2025 22:25:55 +0000
Subject: [PATCH] day 10 part 2 solution!

---
 day10/sol2.go | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/day10/sol2.go b/day10/sol2.go
index 74d1d0a..374669d 100644
--- a/day10/sol2.go
+++ b/day10/sol2.go
@@ -229,11 +229,19 @@ func solveJolts(target Jolts, pool []uint32) int {
 		mask := this.jolts.BitSlice(bit)
 		log.Printf("jolts = %v, bit = %d, mask = %0*b", this.jolts, bit, ntargets, mask)
 
+		// We can't short circuit mask==0
+		// Consider this set of buttons:
+		// (2) (0,3,4,5,6,7) (0,4,5,6,7) (1,2,3,5) (0,1,2,3,4,6,7) (0,2,3,5) {42,20,50,40,32,36,32,32}
+		// with masks 100 11111001 11110001 101110 11011111 101101.
+		// There is no way to combine the buttons that results in mask 00000101
+		// but! there is a way to press them that results in the zero mask 00000000
+		// and has joltage 2,2,2,2,2,2,2,2
+		// (press the third, fourth and fifth button)
+		// if we use that solution for the low bits then for the next bits
+		// we have to find 11111010 instead, which is possible (the second, fourth, and sixth buttons)
+
 		if mask == 0 {
 			seen[this.jolts] = false
-			this.mask += 1
-			qu.AddNode(this)
-			continue
 		}
 
 		for _, n := range bitcost.best(mask) {