From 80142a25fb95b474b024458889f92a16d61d7d99 Mon Sep 17 00:00:00 2001
From: David Ashby <delta.mu.alpha@gmail.com>
Date: Tue, 15 Dec 2020 17:54:04 -0500
Subject: [PATCH] part 2 doesn't work yet

---
 14/main.go | 148 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 14/main.go

diff --git a/14/main.go b/14/main.go
new file mode 100644
index 0000000..404cc72
--- /dev/null
+++ b/14/main.go
@@ -0,0 +1,148 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func main() {
+	start := time.Now()
+	partOne()
+	duration := time.Since(start)
+	partTwo()
+	duration2 := time.Since(start)
+	fmt.Printf("p1: %s, p2: %s\n", duration, duration2-duration)
+}
+
+type bitset struct {
+	bits []string
+}
+
+func newBitset(i int) bitset {
+	b := strings.Split(fmt.Sprintf("%036b", i), "")
+	bs := bitset{
+		bits: strings.Split("000000000000000000000000000000000000", ""),
+	}
+	for i, bt := range b {
+		if bt != "0" {
+			bs.bits[i] = bt
+		}
+	}
+	return bs
+}
+
+func (b bitset) ToInt() int {
+	i, _ := strconv.ParseInt(strings.Join(b.bits, ""), 2, 64)
+	return int(i)
+}
+
+func parseMask(s string) string {
+	return strings.Split(s, " = ")[1]
+}
+
+func parseMemoryToAddrAndBitset(s string) (int, bitset) {
+	a := strings.Split(s, " = ")
+	addr, _ := strconv.Atoi(strings.TrimFunc(a[0], func(r rune) bool {
+		if r == 'm' || r == 'e' || r == '[' || r == ']' {
+			return true
+		}
+		return false
+	}))
+	i, _ := strconv.Atoi(a[1])
+	return addr, newBitset(i)
+}
+
+func parseMemoryToBitsetAndValue(s string) (bitset, int) {
+	a := strings.Split(s, " = ")
+	addr, _ := strconv.Atoi(strings.TrimFunc(a[0], func(r rune) bool {
+		if r == 'm' || r == 'e' || r == '[' || r == ']' {
+			return true
+		}
+		return false
+	}))
+	i, _ := strconv.Atoi(a[1])
+	return newBitset(addr), i
+}
+
+func applyMaskToValue(m string, b bitset) int {
+	for i, r := range m {
+		if r == '0' {
+			b.bits[i] = "0"
+		}
+		if r == '1' {
+			b.bits[i] = "1"
+		}
+	}
+	return b.ToInt()
+}
+
+func applyMaskToAddr(prefix []string, m string, attr bitset) []bitset {
+	if len(m) == 0 {
+		return []bitset{{bits: prefix}}
+	}
+	res := []bitset{}
+	for _, r := range m {
+		if r == '0' || r == 'X' {
+			res = append(res, applyMaskToAddr(append(prefix[:], "0"), m[1:], attr)...)
+		}
+		if r == '1' || r == 'X' {
+			res = append(res, applyMaskToAddr(append(prefix[:], "1"), m[1:], attr)...)
+		}
+	}
+	return res
+}
+
+func partOne() {
+	f, _ := os.Open("input")
+	reader := bufio.NewReader(f)
+	scanner := bufio.NewScanner(reader)
+
+	mem := map[int]int{}
+	var currentMask string
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, "mask") {
+			currentMask = parseMask(line)
+		} else {
+			addr, value := parseMemoryToAddrAndBitset(line)
+			mem[addr] = applyMaskToValue(currentMask, value)
+		}
+	}
+	sum := 0
+	for _, v := range mem {
+		sum = sum + v
+	}
+	fmt.Println(sum)
+}
+
+func partTwo() {
+	f, _ := os.Open("testinput")
+	reader := bufio.NewReader(f)
+	scanner := bufio.NewScanner(reader)
+
+	mem := map[int]int{}
+	var currentMask string
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(line, "mask") {
+			currentMask = parseMask(line)
+		} else {
+			addr, value := parseMemoryToBitsetAndValue(line)
+			for _, b := range applyMaskToAddr([]string{}, currentMask, addr) {
+				mem[b.ToInt()] = value
+			}
+		}
+	}
+
+	sum := 0
+	for _, v := range mem {
+		sum = sum + v
+	}
+	fmt.Println(sum)
+}