2017 Day 23 Complete

2017/day23/.gitignore

@@ -0,0 +1,3 @@
+day23-part2
+day23-part1
+test

2017/day23/day23-part1.go

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+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	inp := StdinToStrings()
+	run(inp)
+}
+
+var reg map[string]int
+
+func run(inp []string) {
+	reg = make(map[string]int)
+	reg["a"] = 1
+	var mulCount int
+
+	var instCnt int
+	for i := 0; i >= 0 && i < len(inp); i++ {
+		instCnt++
+		if instCnt%10 == 0 {
+			ClearScreen()
+			printInstructions(inp, i)
+		}
+		pts := strings.Split(inp[i], " ")
+		if pts[1] == "h" || pts[2] == "h" {
+			fmt.Println("Hit h")
+		}
+		switch pts[0] {
+		case "set":
+			setReg(pts[1], pts[2])
+		case "sub":
+			subReg(pts[1], pts[2])
+		case "mul":
+			mulCount++
+			mulReg(pts[1], pts[2])
+		case "jnz":
+			i += jumpNotZero(pts[1], pts[2])
+		}
+	}
+
+	fmt.Println("Result (H):", reg["h"])
+}
+
+func setReg(key string, val string) {
+	reg[key] = getValue(val)
+}
+
+func subReg(key string, val string) {
+	reg[key] = getValue(key) - getValue(val)
+}
+
+func mulReg(key string, val string) {
+	reg[key] = getValue(key) * getValue(val)
+}
+
+func jumpNotZero(test string, jump string) int {
+	var ret int
+	if getValue(test) != 0 {
+		ret = getValue(jump) - 1
+	}
+	return ret
+}
+
+func getValue(key string) int {
+	var ret int
+	var ok bool
+	var err error
+	if ret, err = strconv.Atoi(key); err != nil {
+		// It's not a number
+		if ret, ok = reg[key]; !ok {
+			// The register is empty
+			reg[key] = 0
+			ret = 0
+		}
+	}
+	return ret
+}
+
+func PrintRegisters() {
+	fmt.Print("[ ")
+	for i := 0; i < 26; i++ {
+		getReg := string('a' + i)
+		fmt.Printf("%s:%d ", getReg, getValue(getReg))
+	}
+	fmt.Print("]\n")
+}
+
+func printInstructions(inp []string, pos int) {
+	PrintRegisters()
+	for i := range inp {
+		if i == pos {
+			fmt.Print("> ", inp[i], "\n")
+		} else {
+			fmt.Print("  ", inp[i], "\n")
+		}
+	}
+}
+
+func ClearScreen() {
+	fmt.Print("\033[H\033[2J")
+}
+
+func StdinToStrings() []string {
+	var input []string
+	scanner := bufio.NewScanner(os.Stdin)
+	for scanner.Scan() {
+		input = append(input, scanner.Text())
+	}
+	return input
+}

2017/day23/day23-part2.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+func main() {
+	var a, b, c, d, e, f, g, h int
+	// Suppress go warnings
+	_, _, _, _, _, _, _, _ = a, b, c, d, e, f, g, h
+	// Derived from test.go
+	b = 109900
+	c = 126900
+
+	// Unoptimized:
+	/*
+		for ; b < c+1; b += 17 {
+			f = 1
+			for d = 2; d < b+1; d++ {
+				for e = 2; e < b+1; e++ {
+					if d*e == b {
+						f = 0
+					}
+				}
+			}
+			// When is f 0?
+			// when d*e == b for "certain values" of b
+			fmt.Println(d, e, b)
+			if f == 0 {
+				h++
+			}
+			// b = 109900
+		}
+	*/
+
+	// Optimized
+	for ; b < c+1; b += 17 {
+		if !IsPrime(b) {
+			h++
+		}
+	}
+
+	fmt.Println(h)
+}
+
+func IsPrime(value int) bool {
+	for i := 2; i <= int(math.Floor(float64(value)/2)); i++ {
+		if value%i == 0 {
+			return false
+		}
+	}
+	return value > 1
+}

2017/day23/input

@@ -0,0 +1,32 @@
+set b 99
+set c b
+jnz a 2
+jnz 1 5
+mul b 100
+sub b -100000
+set c b
+sub c -17000
+set f 1
+set d 2
+set e 2
+set g d
+mul g e
+sub g b
+jnz g 2
+set f 0
+sub e -1
+set g e
+sub g b
+jnz g -8
+sub d -1
+set g d
+sub g b
+jnz g -13
+jnz f 2
+sub h -1
+set g b
+sub g c
+jnz g 0
+jnz 1 3
+sub b -17
+jnz 1 -23

2017/day23/input-disassemble

@@ -0,0 +1,52 @@
+b = 99
+c = b
+if a != 0 {
+  b = b * 100
+  b = b + 100000
+  c = b
+  c = c + 17000
+}
+// b = 109900
+// c = 126900
+
+for {
+  f = 1
+  d = 2
+  for {
+    e = 2
+    g = d
+    for {
+      g = g * e
+      g = g - b
+
+      if g == 0 {
+        f = 0
+      }
+
+      e = e + 1
+      g = e
+      g = g - b
+      if g != 0 {
+        break
+      }
+    }
+
+    d = d + 1
+    g = d
+    g = g - b
+    if g != 0 {
+      break
+    }
+  }
+  if f == 0 {
+    h = h + 1
+  }
+  g = b
+  g = g - c
+
+  if g == 0 {
+    break
+  }
+  b = b + 17
+}
+

2017/day23/input-loops

@@ -0,0 +1,39 @@
+set b 99
+set c b
+
+jnz a 2
+jnz 1 5
+mul b 100
+sub b -100000
+set c b
+sub c -17000
+
+  set f 1
+  set d 2
+    set e 2
+    set g d
+      mul g e
+      sub g b
+
+      jnz g 2
+      set f 0
+
+      sub e -1
+      set g e
+      sub g b
+      jnz g -8
+    sub d -1
+    set g d
+    sub g b
+    jnz g -13
+
+  jnz f 2
+  sub h -1
+
+  set g b
+  sub g c
+
+  jnz g 0
+  jnz 1 3
+  sub b -17
+  jnz 1 -23

2017/day23/test.go

@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+// Logic before any loops (starting values)
+func main() {
+	var a, b, c int
+	b = 99
+	c = b
+	b = b * 100
+	b = b + 100000
+	c = b
+	c = c + 17000
+	fmt.Println(a, b, c)
+}