Day 5

05/answers.txt

@@ -0,0 +1,2 @@
+6745903
+9168267

05/input.txt

@@ -0,0 +1 @@
+3,225,1,225,6,6,1100,1,238,225,104,0,1102,40,93,224,1001,224,-3720,224,4,224,102,8,223,223,101,3,224,224,1,224,223,223,1101,56,23,225,1102,64,78,225,1102,14,11,225,1101,84,27,225,1101,7,82,224,1001,224,-89,224,4,224,1002,223,8,223,1001,224,1,224,1,224,223,223,1,35,47,224,1001,224,-140,224,4,224,1002,223,8,223,101,5,224,224,1,224,223,223,1101,75,90,225,101,9,122,224,101,-72,224,224,4,224,1002,223,8,223,101,6,224,224,1,224,223,223,1102,36,63,225,1002,192,29,224,1001,224,-1218,224,4,224,1002,223,8,223,1001,224,7,224,1,223,224,223,102,31,218,224,101,-2046,224,224,4,224,102,8,223,223,101,4,224,224,1,224,223,223,1001,43,38,224,101,-52,224,224,4,224,1002,223,8,223,101,5,224,224,1,223,224,223,1102,33,42,225,2,95,40,224,101,-5850,224,224,4,224,1002,223,8,223,1001,224,7,224,1,224,223,223,1102,37,66,225,4,223,99,0,0,0,677,0,0,0,0,0,0,0,0,0,0,0,1105,0,99999,1105,227,247,1105,1,99999,1005,227,99999,1005,0,256,1105,1,99999,1106,227,99999,1106,0,265,1105,1,99999,1006,0,99999,1006,227,274,1105,1,99999,1105,1,280,1105,1,99999,1,225,225,225,1101,294,0,0,105,1,0,1105,1,99999,1106,0,300,1105,1,99999,1,225,225,225,1101,314,0,0,106,0,0,1105,1,99999,1007,226,677,224,1002,223,2,223,1005,224,329,1001,223,1,223,1007,226,226,224,1002,223,2,223,1006,224,344,101,1,223,223,1107,677,226,224,102,2,223,223,1006,224,359,1001,223,1,223,108,677,677,224,1002,223,2,223,1006,224,374,1001,223,1,223,107,677,677,224,1002,223,2,223,1005,224,389,101,1,223,223,8,677,677,224,1002,223,2,223,1005,224,404,1001,223,1,223,108,226,226,224,1002,223,2,223,1005,224,419,101,1,223,223,1008,677,677,224,1002,223,2,223,1005,224,434,101,1,223,223,1008,226,226,224,1002,223,2,223,1005,224,449,101,1,223,223,7,677,226,224,1002,223,2,223,1006,224,464,1001,223,1,223,7,226,226,224,1002,223,2,223,1005,224,479,1001,223,1,223,1007,677,677,224,102,2,223,223,1005,224,494,101,1,223,223,1108,677,226,224,102,2,223,223,1006,224,509,1001,223,1,223,8,677,226,224,102,2,223,223,1005,224,524,1001,223,1,223,1107,226,226,224,102,2,223,223,1006,224,539,1001,223,1,223,1008,226,677,224,1002,223,2,223,1006,224,554,1001,223,1,223,1107,226,677,224,1002,223,2,223,1006,224,569,1001,223,1,223,1108,677,677,224,102,2,223,223,1005,224,584,101,1,223,223,7,226,677,224,102,2,223,223,1006,224,599,1001,223,1,223,1108,226,677,224,102,2,223,223,1006,224,614,101,1,223,223,107,226,677,224,1002,223,2,223,1005,224,629,101,1,223,223,108,226,677,224,1002,223,2,223,1005,224,644,101,1,223,223,8,226,677,224,1002,223,2,223,1005,224,659,1001,223,1,223,107,226,226,224,1002,223,2,223,1006,224,674,101,1,223,223,4,223,99,226

05/main.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"fmt"
+	"github.com/csmith/aoc-2019/common"
+	"github.com/csmith/aoc-2019/intcode"
+)
+
+func last(channel <-chan int) (res int) {
+	for {
+		o, more := <-channel
+		if more {
+			res = o
+		} else {
+			return
+		}
+	}
+}
+
+func main() {
+	input := common.ReadCsvAsInts("05/input.txt")
+	memory := make([]int, len(input))
+	copy(memory, input)
+
+	vm := intcode.NewVirtualMachine(memory)
+	vm.Input <- 1
+	vm.Run()
+	fmt.Println(last(vm.Output))
+
+	vm.Reset(input)
+	vm.Input <- 5
+	vm.Run()
+	fmt.Println(last(vm.Output))
+}

intcode/ops.go

@@ -1,23 +1,78 @@
 package intcode
 
+// ArgFunc provides the value of an argument for an opcode
+type ArgFunc = func(pos int) int
+
 // OpcodeFunc is a function that describes an opcode implemented in the VM.
-type OpcodeFunc = func(vm *VirtualMachine, args []int)
+type OpcodeFunc = func(vm *VirtualMachine, param ArgFunc)
+
+// AddOpcode takes the values specified by args 1 and 2, adds them together, and stores at the memory address given
+// by arg 3.
+func AddOpcode(vm *VirtualMachine, arg ArgFunc) {
+	vm.Memory[vm.Memory[vm.ip+3]] = arg(0) + arg(1)
+	vm.ip += 4
+}
+
+// MulOpcode takes the values specified by args 1 and 2, multiplies them together, and stores at the memory address
+// given by arg 3.
+func MulOpcode(vm *VirtualMachine, arg ArgFunc) {
+	vm.Memory[vm.Memory[vm.ip+3]] = arg(0) * arg(1)
+	vm.ip += 4
+}
+
+// ReadOpCode reads a value from the input stream and stores it at the memory address given by arg 1.
+func ReadOpCode(vm *VirtualMachine, arg ArgFunc) {
+	vm.Memory[vm.Memory[vm.ip+1]] = <-vm.Input
+	vm.ip += 2
+}
+
+// WriteOpCode writes the value specified by the first argument to the output stream.
+func WriteOpCode(vm *VirtualMachine, arg ArgFunc) {
+	vm.Output <- arg(0)
+	vm.ip += 2
+}
+
+// JumpIfTrueOpCode checks if the first argument is not zero, and if so jumps to the second argument.
+func JumpIfTrueOpCode(vm *VirtualMachine, arg ArgFunc) {
+	if arg(0) != 0 {
+		vm.ip = arg(1)
+	} else {
+		vm.ip += 3
+	}
+}
+
+// JumpIfFalseOpCode checks if the first argument is zero, and if so jumps to the second argument.
+func JumpIfFalseOpCode(vm *VirtualMachine, arg ArgFunc) {
+	if arg(0) == 0 {
+		vm.ip = arg(1)
+	} else {
+		vm.ip += 3
+	}
+}
 
-// AddOpcode takes the values from the memory addresses given by args 1 and 2, adds them together,
-// and stores at the memory address given by arg 3.
-func AddOpcode(vm *VirtualMachine, args []int) {
-	vm.Memory[args[2]] = vm.Memory[args[0]] + vm.Memory[args[1]]
+// LessThanOpCode checks if the first argument is less than the second, and stores the result at the address given
+// by the third argument.
+func LessThanOpCode(vm *VirtualMachine, arg ArgFunc) {
+	if arg(0) < arg(1) {
+		vm.Memory[vm.Memory[vm.ip+3]] = 1
+	} else {
+		vm.Memory[vm.Memory[vm.ip+3]] = 0
+	}
 	vm.ip += 4
 }
 
-// MulOpcode takes the values from the memory addresses given by args 1 and 2, muliplies them together,
-// and stores at the memory address given by arg 3.
-func MulOpcode(vm *VirtualMachine, args []int) {
-	vm.Memory[args[2]] = vm.Memory[args[0]] * vm.Memory[args[1]]
+// EqualsOpCode checks if the first argument is equal to the second, and stores the result at the address given
+// by the third argument.
+func EqualsOpCode(vm *VirtualMachine, arg ArgFunc) {
+	if arg(0) == arg(1) {
+		vm.Memory[vm.Memory[vm.ip+3]] = 1
+	} else {
+		vm.Memory[vm.Memory[vm.ip+3]] = 0
+	}
 	vm.ip += 4
 }
 
 // HaltOpcode halts the VM and takes no arguments.
-func HaltOpcode(vm *VirtualMachine, args []int) {
+func HaltOpcode(vm *VirtualMachine, arg ArgFunc) {
 	vm.Halted = true
 }

intcode/vm.go

@@ -1,11 +1,18 @@
 package intcode
 
+import (
+	"fmt"
+	"math"
+)
+
 // VirtualMachine is an IntCode virtual machine.
 type VirtualMachine struct {
 	ip      int
 	opcodes map[int]OpcodeFunc
 	Memory  []int
 	Halted  bool
+	Input   chan int
+	Output  chan int
 }
 
 // NewVirtualMachine creates a new IntCode virtual machine, initialised
@@ -15,9 +22,17 @@ func NewVirtualMachine(memory []int) *VirtualMachine {
 		ip:     0,
 		Memory: memory,
 		Halted: false,
+		Input:  make(chan int, 100),
+		Output: make(chan int, 100),
 		opcodes: map[int]OpcodeFunc{
 			1:  AddOpcode,
 			2:  MulOpcode,
+			3:  ReadOpCode,
+			4:  WriteOpCode,
+			5:  JumpIfTrueOpCode,
+			6:  JumpIfFalseOpCode,
+			7:  LessThanOpCode,
+			8:  EqualsOpCode,
 			99: HaltOpcode,
 		},
 	}
@@ -26,8 +41,23 @@ func NewVirtualMachine(memory []int) *VirtualMachine {
 // Run repeatedly executes instructions until the VM halts.
 func (vm *VirtualMachine) Run() {
 	for !vm.Halted {
-		vm.opcodes[vm.Memory[vm.ip]](vm, vm.Memory[vm.ip+1:])
+		instruction := vm.Memory[vm.ip]
+		opcode := instruction % 100
+
+		vm.opcodes[opcode](vm, func(pos int) int {
+			mode := (instruction / int(math.Pow10(2+pos))) % 10
+			switch mode {
+			case 0:
+				return vm.Memory[vm.Memory[vm.ip+1+pos]]
+			case 1:
+				return vm.Memory[vm.ip+1+pos]
+			default:
+				panic(fmt.Sprintf("Unknown parameter mode: %d", mode))
+			}
+		})
 	}
+	close(vm.Input)
+	close(vm.Output)
 }
 
 // Reset resets the memory to the given slice, and all other state back to its original value.
@@ -35,4 +65,6 @@ func (vm *VirtualMachine) Reset(memory []int) {
 	copy(vm.Memory, memory)
 	vm.ip = 0
 	vm.Halted = false
+	vm.Input = make(chan int, 100)
+	vm.Output = make(chan int, 100)
 }

intcode/vm_test.go

@@ -24,3 +24,43 @@ func TestDayTwoSamples(t *testing.T) {
 		}
 	}
 }
+
+func TestDayFiveSamples(t *testing.T) {
+	tables := []struct {
+		given  []int
+		input  []int
+		output []int
+	}{
+		// Reads then outputs a number
+		{[]int{3, 0, 4, 0, 99}, []int{123}, []int{123}},
+		// Using position mode, consider whether the input is equal to 8; output 1 (if it is) or 0 (if it is not).
+		{[]int{3, 9, 8, 9, 10, 9, 4, 9, 99, -1, 8}, []int{8}, []int{1}},
+		{[]int{3, 9, 8, 9, 10, 9, 4, 9, 99, -1, 8}, []int{7}, []int{0}},
+		// Using position mode, consider whether the input is less than 8; output 1 (if it is) or 0 (if it is not).
+		{[]int{3, 9, 7, 9, 10, 9, 4, 9, 99, -1, 8}, []int{7}, []int{1}},
+		{[]int{3, 9, 7, 9, 10, 9, 4, 9, 99, -1, 8}, []int{8}, []int{0}},
+		// Using immediate mode, consider whether the input is equal to 8; output 1 (if it is) or 0 (if it is not).
+		{[]int{3, 3, 1108, -1, 8, 3, 4, 3, 99}, []int{8}, []int{1}},
+		{[]int{3, 3, 1108, -1, 8, 3, 4, 3, 99}, []int{9}, []int{0}},
+		// Using immediate mode, consider whether the input is less than 8; output 1 (if it is) or 0 (if it is not).
+		{[]int{3, 3, 1107, -1, 8, 3, 4, 3, 99}, []int{0}, []int{1}},
+		{[]int{3, 3, 1107, -1, 8, 3, 4, 3, 99}, []int{10}, []int{0}},
+	}
+
+	for _, table := range tables {
+		vm := NewVirtualMachine(table.given)
+
+		for _, v := range table.input {
+			vm.Input <- v
+		}
+
+		vm.Run()
+
+		for _, v := range table.output {
+			actual := <-vm.Output
+			if !reflect.DeepEqual(v, actual) {
+				t.Errorf("Wrong output value received for %v, got: %v, want: %v.", table.given, actual, v)
+			}
+		}
+	}
+}