From 9f412dbd296eea57b8121d6247a58229da716632 Mon Sep 17 00:00:00 2001
From: Brian Buller <brian@bullercodeworks.com>
Date: Thu, 10 Dec 2020 09:31:02 -0600
Subject: [PATCH] Day 10 possibly complete

but way to resource intensive
---
 2020/day10/input      |  97 ++++++++++++++++++++++++++++++++++
 2020/day10/main.go    | 117 ++++++++++++++++++++++++++++++++++++++++++
 2020/day10/out        |  40 +++++++++++++++
 2020/day10/testinput  |  11 ++++
 2020/day10/testinput2 |  31 +++++++++++
 5 files changed, 296 insertions(+)
 create mode 100644 2020/day10/input
 create mode 100644 2020/day10/main.go
 create mode 100644 2020/day10/out
 create mode 100644 2020/day10/testinput
 create mode 100644 2020/day10/testinput2

diff --git a/2020/day10/input b/2020/day10/input
new file mode 100644
index 0000000..5b4b267
--- /dev/null
+++ b/2020/day10/input
@@ -0,0 +1,97 @@
+8
+131
+91
+35
+47
+116
+105
+121
+56
+62
+94
+72
+13
+82
+156
+102
+12
+59
+31
+138
+46
+120
+7
+127
+126
+111
+2
+123
+22
+69
+18
+157
+75
+149
+88
+81
+23
+98
+132
+1
+63
+142
+37
+133
+61
+112
+122
+128
+155
+145
+139
+66
+42
+134
+24
+60
+9
+28
+17
+29
+101
+148
+96
+68
+25
+19
+6
+67
+113
+55
+40
+135
+97
+79
+48
+159
+14
+43
+86
+36
+41
+85
+87
+119
+30
+108
+80
+152
+158
+151
+32
+78
+150
+95
+3
+52
+49
diff --git a/2020/day10/main.go b/2020/day10/main.go
new file mode 100644
index 0000000..8cdcaed
--- /dev/null
+++ b/2020/day10/main.go
@@ -0,0 +1,117 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
+
+func main() {
+	fmt.Println("# Day 10")
+	inp := h.StdinToIntSlice()
+	sort.Ints(inp)
+	jumps := part1(inp)
+	fmt.Println("## Part 1")
+	fmt.Println(jumps[1] * jumps[3])
+
+	fmt.Println("## Part 2")
+	fmt.Println(part2(inp))
+}
+
+func part1(inp []int) map[int]int {
+	jumps := make(map[int]int)
+	var curr int
+	var used []int
+	wrk := make([]int, len(inp))
+	copy(wrk, inp)
+	for len(used) < len(inp) {
+		var next int
+		for i := range wrk {
+			if i == 0 {
+				next = wrk[i]
+			} else {
+				diff := wrk[i] - curr
+				if diff > 0 && diff < next-curr {
+					next = wrk[i]
+				}
+			}
+		}
+		jumps[next-curr]++
+		curr = next
+		used = append(used, curr)
+		var nextList []int
+		for i := range wrk {
+			if wrk[i] != curr {
+				nextList = append(nextList, wrk[i])
+			}
+		}
+		wrk = make([]int, len(nextList))
+		copy(wrk, nextList)
+	}
+	jumps[3]++
+	return jumps
+}
+
+var prevs map[int][]int
+var psbs map[int][][]int
+
+func part2(inp []int) int {
+	psbs = make(map[int][][]int)
+	psbs[0] = [][]int{{0}}
+	prevs = make(map[int][]int)
+	var phone int
+	for i := range inp {
+		if inp[i] > phone {
+			phone = inp[i]
+		}
+	}
+	// Add the outlet
+	inp = append(inp, 0)
+	// Add the phone
+	phone = phone + 3
+	inp = append(inp, phone)
+	for i := range inp {
+		prevs[inp[i]] = findPrevPoss(inp[i], inp)
+	}
+
+	total := len(findConfigs(phone))
+	return total
+}
+
+func findConfigs(curr int) [][]int {
+	if p, ok := psbs[curr]; ok {
+		return p
+	} else {
+		var ret [][]int
+		for _, v := range prevs[curr] {
+			rec := findConfigs(v)
+			if len(rec) > 0 {
+				for _, rv := range rec {
+					ret = append(ret, append([]int{curr}, rv...))
+				}
+			} else {
+				ret = [][]int{{curr}}
+			}
+		}
+		psbs[curr] = ret
+		return ret
+	}
+}
+
+// Find the options immediately preceeding curr
+func findPrevPoss(curr int, inp []int) []int {
+	if curr == 0 {
+		return []int{}
+	}
+	var next []int
+	for i := range inp {
+		if inp[i] >= curr {
+			continue
+		}
+		if curr-inp[i] <= 3 {
+			next = append(next, inp[i])
+		}
+	}
+	return next
+}
diff --git a/2020/day10/out b/2020/day10/out
new file mode 100644
index 0000000..80fc522
--- /dev/null
+++ b/2020/day10/out
@@ -0,0 +1,40 @@
+# Day 10
+## Part 1
+35
+## Part 2
+22 Finding configs
+22 Digging
+19 Finding configs
+19 Digging
+16 Finding configs
+16 Digging
+15 Finding configs
+15 Digging
+12 Finding configs
+12 Digging
+10 Finding configs
+10 Digging
+7 Finding configs
+7 Digging
+4 Finding configs
+4 Digging
+1 Finding configs
+1 Digging
+0 Finding configs
+0 Already known []
+5 Finding configs
+5 Digging
+4 Finding configs
+4 Already known [[4 1]]
+6 Finding configs
+6 Digging
+4 Finding configs
+4 Already known [[4 1]]
+5 Finding configs
+5 Already known [[5 4 1]]
+11 Finding configs
+11 Digging
+10 Finding configs
+10 Already known [[10 7 4 1] [10 7 5 4 1] [10 7 6 4 1] [10 7 6 5 4 1]]
+map[0:[] 1:[[1]] 4:[[4 1]] 5:[[5 4 1]] 6:[[6 4 1] [6 5 4 1]] 7:[[7 4 1] [7 5 4 1] [7 6 4 1] [7 6 5 4 1]] 10:[[10 7 4 1] [10 7 5 4 1] [10 7 6 4 1] [10 7 6 5 4 1]] 11:[[11 10 7 4 1] [11 10 7 5 4 1] [11 10 7 6 4 1] [11 10 7 6 5 4 1]] 12:[[12 10 7 4 1] [12 10 7 5 4 1] [12 10 7 6 4 1] [12 10 7 6 5 4 1] [12 11 10 7 4 1] [12 11 10 7 5 4 1] [12 11 10 7 6 4 1] [12 11 10 7 6 5 4 1]] 15:[[15 12 10 7 4 1] [15 12 10 7 5 4 1] [15 12 10 7 6 4 1] [15 12 10 7 6 5 4 1] [15 12 11 10 7 4 1] [15 12 11 10 7 5 4 1] [15 12 11 10 7 6 4 1] [15 12 11 10 7 6 5 4 1]] 16:[[16 15 12 10 7 4 1] [16 15 12 10 7 5 4 1] [16 15 12 10 7 6 4 1] [16 15 12 10 7 6 5 4 1] [16 15 12 11 10 7 4 1] [16 15 12 11 10 7 5 4 1] [16 15 12 11 10 7 6 4 1] [16 15 12 11 10 7 6 5 4 1]] 19:[[19 16 15 12 10 7 4 1] [19 16 15 12 10 7 5 4 1] [19 16 15 12 10 7 6 4 1] [19 16 15 12 10 7 6 5 4 1] [19 16 15 12 11 10 7 4 1] [19 16 15 12 11 10 7 5 4 1] [19 16 15 12 11 10 7 6 4 1] [19 16 15 12 11 10 7 6 5 4 1]] 22:[[22 19 16 15 12 10 7 4 1] [22 19 16 15 12 10 7 5 4 1] [22 19 16 15 12 10 7 6 4 1] [22 19 16 15 12 10 7 6 5 4 1] [22 19 16 15 12 11 10 7 4 1] [22 19 16 15 12 11 10 7 5 4 1] [22 19 16 15 12 11 10 7 6 4 1] [22 19 16 15 12 11 10 7 6 5 4 1]]]
+8
diff --git a/2020/day10/testinput b/2020/day10/testinput
new file mode 100644
index 0000000..ec4a03f
--- /dev/null
+++ b/2020/day10/testinput
@@ -0,0 +1,11 @@
+16
+10
+15
+5
+1
+11
+7
+19
+6
+12
+4
diff --git a/2020/day10/testinput2 b/2020/day10/testinput2
new file mode 100644
index 0000000..e6376dc
--- /dev/null
+++ b/2020/day10/testinput2
@@ -0,0 +1,31 @@
+28
+33
+18
+42
+31
+14
+46
+20
+48
+47
+24
+23
+49
+45
+19
+38
+39
+11
+1
+32
+25
+35
+8
+17
+7
+9
+4
+2
+34
+10
+3