Day Two

1 files changed, 66 insertions, 0 deletions

diff --git a/two.go b/two.go
new file mode 100644
index 0000000..8108c87
--- /dev/null
+++ b/two.go
@@ -0,0 +1,66 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strconv"
+)
+
+func main() {
+	var slice []int
+	start, size := 0, 0
+	if len(os.Args) < 2 {
+		panic("runtime error: missing operand")
+	}
+	file, err := ioutil.ReadFile(os.Args[1])
+	if err != nil {
+		panic(err)
+	}
+	for i := 0; i < len(file); i++ {
+		if file[i] == ',' || file[i] == '\n' {
+			arg, err := strconv.Atoi(string(file[start:i])) // i-1??
+			if err != nil {
+				panic(err)
+			}
+			slice = append(slice, arg)
+			start = i + 1
+			size++
+		}
+	}
+	noun, verb := edocpo(slice, 19690720)
+	slice[1] = 12
+	slice[2] = 2
+	fmt.Println(opcode(slice)[0])
+	fmt.Println(100*noun + verb)
+}
+
+func opcode(slice []int) []int {
+	for i := 0; i < len(slice); i += 4 {
+		if slice[i] == 1 {
+			slice[slice[i+3]] = slice[slice[i+1]] + slice[slice[i+2]]
+		} else if slice[i] == 2 {
+			slice[slice[i+3]] = slice[slice[i+1]] * slice[slice[i+2]]
+		} else if slice[i] == 99 {
+			return slice
+		} else {
+			fmt.Println("Unsupported code", slice[i], "at", i)
+			os.Exit(0)
+		}
+	}
+	return slice
+}
+
+func edocpo(slice []int, output int) (int, int) {
+	var ecils []int
+	for i := 0; i < len(slice); i++ {
+		for j := 0; j < len(slice); j++ {
+			ecils = append([]int(nil), slice...) // reset ecils to slice
+			ecils[1], ecils[2] = i, j
+			if opcode(ecils)[0] == output {
+				return i, j
+			}
+		}
+	}
+	return -1, -1
+}