Implementation for 5b

challenge/day5/b.go

@@ -0,0 +1,35 @@
+package day5
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/nlowe/aoc2019/challenge"
+	"github.com/nlowe/aoc2019/intcode"
+	"github.com/nlowe/aoc2019/intcode/input"
+	"github.com/spf13/cobra"
+)
+
+var B = &cobra.Command{
+	Use:   "5b",
+	Short: "Day 5, Problem B",
+	Run: func(_ *cobra.Command, _ []string) {
+		fmt.Printf("Answer: %d\n", b(challenge.FromFile()))
+	},
+}
+
+func b(challenge *challenge.Input) int {
+	cpu, output := intcode.NewCPUForProgram(<-challenge.Lines(), input.NewFixed(5))
+
+	code := 0
+	wg := sync.WaitGroup{}
+	wg.Add(1)
+	go func() {
+		code = <-output
+		wg.Done()
+	}()
+
+	cpu.Run()
+	wg.Wait()
+	return code
+}

intcode/cpu.go

@@ -12,6 +12,10 @@ const (
 	OpMul  = 2
 	OpIn   = 3
 	OpOut  = 4
+	OpJT   = 5
+	OpJF   = 6
+	OpLT   = 7
+	OpEQ   = 8
 	OpHalt = 99
 
 	ModeIndirect  = 0
@@ -66,6 +70,34 @@ func (c *CPU) Step() {
 	case OpOut:
 		c.outputs <- c.read(m1, c.Memory[c.pc+1])
 		c.pc += 2
+	case OpJT:
+		if c.read(m1, c.Memory[c.pc+1]) != 0 {
+			c.pc = c.read(m2, c.Memory[c.pc+2])
+		} else {
+			c.pc += 3
+		}
+	case OpJF:
+		if c.read(m1, c.Memory[c.pc+1]) == 0 {
+			c.pc = c.read(m2, c.Memory[c.pc+2])
+		} else {
+			c.pc += 3
+		}
+	case OpLT:
+		if c.read(m1, c.Memory[c.pc+1]) < c.read(m2, c.Memory[c.pc+2]) {
+			c.write(m3, c.Memory[c.pc+3], 1)
+		} else {
+			c.write(m3, c.Memory[c.pc+3], 0)
+		}
+
+		c.pc += 4
+	case OpEQ:
+		if c.read(m1, c.Memory[c.pc+1]) == c.read(m2, c.Memory[c.pc+2]) {
+			c.write(m3, c.Memory[c.pc+3], 1)
+		} else {
+			c.write(m3, c.Memory[c.pc+3], 0)
+		}
+
+		c.pc += 4
 	case OpHalt:
 		close(c.outputs)
 		return

intcode/cpu_test.go

@@ -1,6 +1,8 @@
 package intcode
 
 import (
+	"fmt"
+	"strconv"
 	"sync"
 	"testing"
 
@@ -65,3 +67,93 @@ func TestCPU_IO(t *testing.T) {
 	sut.Run()
 	wg.Wait()
 }
+
+func TestCPU_Compare(t *testing.T) {
+	tests := []struct {
+		program  string
+		input    <-chan int
+		expected int
+	}{
+		{program: "3,9,8,9,10,9,4,9,99,-1,8", input: input.NewFixed(8), expected: 1},
+		{program: "3,9,8,9,10,9,4,9,99,-1,8", input: input.NewFixed(42), expected: 0},
+		{program: "3,9,7,9,10,9,4,9,99,-1,8", input: input.NewFixed(7), expected: 1},
+		{program: "3,9,7,9,10,9,4,9,99,-1,8", input: input.NewFixed(42), expected: 0},
+		{program: "3,3,1108,-1,8,3,4,3,99", input: input.NewFixed(8), expected: 1},
+		{program: "3,3,1108,-1,8,3,4,3,99", input: input.NewFixed(42), expected: 0},
+		{program: "3,3,1107,-1,8,3,4,3,99", input: input.NewFixed(7), expected: 1},
+		{program: "3,3,1107,-1,8,3,4,3,99", input: input.NewFixed(42), expected: 0},
+	}
+
+	for _, tt := range tests {
+		t.Run(fmt.Sprintf("%s=%d", tt.program, tt.expected), func(t *testing.T) {
+			cpu, output := NewCPUForProgram(tt.program, tt.input)
+
+			wg := sync.WaitGroup{}
+			wg.Add(1)
+			go func() {
+				require.Equal(t, tt.expected, <-output)
+				wg.Done()
+			}()
+
+			cpu.Run()
+			wg.Wait()
+		})
+	}
+}
+
+func TestCPU_Jump(t *testing.T) {
+	tests := []struct {
+		program  string
+		input    <-chan int
+		expected int
+	}{
+		{program: "3,12,6,12,15,1,13,14,13,4,13,99,-1,0,1,9", input: input.NewFixed(0), expected: 0},
+		{program: "3,12,6,12,15,1,13,14,13,4,13,99,-1,0,1,9", input: input.NewFixed(42), expected: 1},
+		{program: "3,3,1105,-1,9,1101,0,0,12,4,12,99,1", input: input.NewFixed(0), expected: 0},
+		{program: "3,3,1105,-1,9,1101,0,0,12,4,12,99,1", input: input.NewFixed(42), expected: 1},
+	}
+
+	for _, tt := range tests {
+		t.Run(fmt.Sprintf("%s=%d", tt.program, tt.expected), func(t *testing.T) {
+			cpu, output := NewCPUForProgram(tt.program, tt.input)
+
+			wg := sync.WaitGroup{}
+			wg.Add(1)
+			go func() {
+				require.Equal(t, tt.expected, <-output)
+				wg.Done()
+			}()
+
+			cpu.Run()
+			wg.Wait()
+		})
+	}
+}
+
+func TestCPU_CmpAndJump(t *testing.T) {
+	tests := []struct {
+		program  string
+		input    <-chan int
+		expected int
+	}{
+		{program: "3,21,1008,21,8,20,1005,20,22,107,8,21,20,1006,20,31,1106,0,36,98,0,0,1002,21,125,20,4,20,1105,1,46,104,999,1105,1,46,1101,1000,1,20,4,20,1105,1,46,98,99", input: input.NewFixed(7), expected: 999},
+		{program: "3,21,1008,21,8,20,1005,20,22,107,8,21,20,1006,20,31,1106,0,36,98,0,0,1002,21,125,20,4,20,1105,1,46,104,999,1105,1,46,1101,1000,1,20,4,20,1105,1,46,98,99", input: input.NewFixed(8), expected: 1000},
+		{program: "3,21,1008,21,8,20,1005,20,22,107,8,21,20,1006,20,31,1106,0,36,98,0,0,1002,21,125,20,4,20,1105,1,46,104,999,1105,1,46,1101,1000,1,20,4,20,1105,1,46,98,99", input: input.NewFixed(9), expected: 1001},
+	}
+
+	for _, tt := range tests {
+		t.Run(strconv.Itoa(tt.expected), func(t *testing.T) {
+			cpu, output := NewCPUForProgram(tt.program, tt.input)
+
+			wg := sync.WaitGroup{}
+			wg.Add(1)
+			go func() {
+				require.Equal(t, tt.expected, <-output)
+				wg.Done()
+			}()
+
+			cpu.Run()
+			wg.Wait()
+		})
+	}
+}

main.go

@@ -50,7 +50,7 @@ func init() {
 		day2.A, day2.B,
 		day3.A, day3.B,
 		day4.A, day4.B,
-		day5.A,
+		day5.A, day5.B,
 	)
 
 	flags := rootCmd.PersistentFlags()