Day 7

07/answers.txt

@@ -0,0 +1,2 @@
+255590
+58285150

07/input.txt

@@ -0,0 +1 @@
+3,8,1001,8,10,8,105,1,0,0,21,42,63,76,101,114,195,276,357,438,99999,3,9,101,2,9,9,102,5,9,9,1001,9,3,9,1002,9,5,9,4,9,99,3,9,101,4,9,9,102,5,9,9,1001,9,5,9,102,2,9,9,4,9,99,3,9,1001,9,3,9,1002,9,5,9,4,9,99,3,9,1002,9,2,9,101,5,9,9,102,3,9,9,101,2,9,9,1002,9,3,9,4,9,99,3,9,101,3,9,9,102,2,9,9,4,9,99,3,9,1001,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,101,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,101,1,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,1,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,1,9,4,9,99,3,9,102,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,1001,9,1,9,4,9,3,9,102,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,102,2,9,9,4,9,99,3,9,102,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,1001,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,1001,9,1,9,4,9,3,9,1002,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,101,2,9,9,4,9,3,9,1001,9,2,9,4,9,99,3,9,1001,9,1,9,4,9,3,9,101,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,1,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,2,9,4,9,99,3,9,102,2,9,9,4,9,3,9,101,1,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,101,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,101,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,101,2,9,9,4,9,99

07/main.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"fmt"
+	"github.com/csmith/aoc-2019/common"
+	"github.com/csmith/aoc-2019/intcode"
+)
+
+func copyOf(memory []int) []int {
+	res := make([]int, len(memory))
+	copy(res, memory)
+	return res
+}
+
+func runPipeline(program []int, ps []int, feedback bool) int {
+	// Create a series of VMs for our amplifiers
+	vms := make([]*intcode.VirtualMachine, len(ps))
+	for i := 0; i < len(ps); i++ {
+		vms[i] = intcode.NewVirtualMachine(copyOf(program), true)
+	}
+
+	// Link all the inputs and outputs
+	for i, vm := range vms {
+		if i > 0 {
+			vm.Input = vms[i-1].Output
+		} else if feedback {
+			vm.Input = vms[len(vms)-1].Output
+		}
+	}
+
+	// Seed the phase settings
+	for i, vm := range vms {
+		vm.Input <- ps[i]
+	}
+
+	// Background run all but the last VM
+	for _, vm := range vms[:len(vms)-1] {
+		go vm.Run()
+	}
+
+	// Kick off the first VM and then wait for the last VM to finish
+	vms[0].Input <- 0
+	vms[len(vms)-1].Run()
+
+	// Snag the left over value from the last VM's output
+	return <-vms[len(vms)-1].Output
+}
+
+func maxOutput(input []int, ps []int, feedback bool) int {
+	max := 0
+	for _, p := range common.Permutations(ps) {
+		val := runPipeline(input, p, feedback)
+		if val > max {
+			max = val
+		}
+	}
+	return max
+}
+
+func main() {
+	input := common.ReadCsvAsInts("07/input.txt")
+	fmt.Println(maxOutput(input, []int{0, 1, 2, 3, 4}, false))
+	fmt.Println(maxOutput(input, []int{5, 6, 7, 8, 9}, true))
+}

common/geometry.go

@@ -1,28 +0,0 @@
-package common
-
-import (
-	"fmt"
-)
-
-// Point represents a point on a 2D grid.
-type Point struct {
-	X, Y int64
-}
-
-// Plus returns a new Point which is the sum of this point and the other point.
-func (p Point) Plus(p2 Point) Point {
-	return Point{
-		X: p.X + p2.X,
-		Y: p.Y + p2.Y,
-	}
-}
-
-// String returns a user-friendly string for debugging purposes.
-func (p Point) String() string {
-	return fmt.Sprintf("(%d, %d)", p.X, p.Y)
-}
-
-// Manhattan calculates the Manhattan distance between this point and the other point.
-func (p Point) Manhattan(other Point) int64 {
-	return Abs(p.X-other.X) + Abs(p.Y-other.Y)
-}

common/itertools.go

@@ -0,0 +1,21 @@
+package common
+
+// Permutations returns all possible permutations of the given ints.
+// Source: https://github.com/dolotech/datastructures-algorithms/blob/master/NUMERICSLICEPERMUTATIONGENERATOR.md
+func Permutations(xs []int) (res [][]int) {
+	var rc func([]int, int)
+	rc = func(a []int, k int) {
+		if k == len(a) {
+			res = append(res, append([]int{}, a...))
+		} else {
+			for i := k; i < len(xs); i++ {
+				a[k], a[i] = a[i], a[k]
+				rc(a, k+1)
+				a[k], a[i] = a[i], a[k]
+			}
+		}
+	}
+	rc(xs, 0)
+
+	return res
+}

intcode/vm.go

@@ -65,8 +65,7 @@ func (vm *VirtualMachine) Run() {
 
 		vm.opcodes[opcode].(OpcodeFunc)(vm)
 	}
-	if vm.Input != nil {
-		close(vm.Input)
+	if vm.Output != nil {
 		close(vm.Output)
 	}
 }