2018 day 19 complete

2018/day19/day19.go

@@ -12,19 +12,19 @@ import (
 
 func main() {
 	input := stdinToStringSlice()
-	part1(input)
+	//part1(input)
+	part2(input)
 }
 
 func part1(input []string) {
 	vpc := NewState()
-	vpc.reg[0] = 1
 	if strings.HasPrefix(input[0], "#ip") {
 		// Binding the ip to a register...
 		pts := strings.Split(input[0], " ")
 		vpc.ipReg = Atoi(pts[1])
 		input = input[1:]
 	}
-	for i := 0; i < 1000000; i++ {
+	for i := 0; i < 200; i++ {
 		if vpc.ip >= len(input) {
 			break
 		}
@@ -33,7 +33,9 @@ func part1(input []string) {
 			if vpc.ipReg > -1 {
 				vpc.reg[vpc.ipReg] = vpc.ip
 			}
+			fmt.Print(vpc.string(), " -> ", op, " ", cmd, " -> ")
 			vpc.run(op, cmd)
+			fmt.Println(vpc.string())
 			vpc.ip = vpc.reg[vpc.ipReg]
 		}
 		vpc.ip++
@@ -41,6 +43,44 @@ func part1(input []string) {
 	fmt.Println(vpc.string())
 }
 
+func part2(input []string) {
+	vpc := NewState()
+	vpc.reg[0] = 1
+	if strings.HasPrefix(input[0], "#ip") {
+		// Binding the ip to a register...
+		pts := strings.Split(input[0], " ")
+		vpc.ipReg = Atoi(pts[1])
+		input = input[1:]
+	}
+
+	for {
+		if vpc.ip >= len(input) {
+			break
+		}
+		if vpc.ip == 3 {
+			// When ip == 3, we kick off the loop.
+			// Looks like it's just summing the divisors of the value in register 2
+			divisors := getDivisors(vpc.reg[2])
+			fmt.Println(divisors)
+			fmt.Println(sum(divisors))
+			break
+		} else {
+			// Normal Execution
+			inp := input[vpc.ip]
+			if op, cmd, err := vpc.parseCommand(inp); err == nil {
+				if vpc.ipReg > -1 {
+					vpc.reg[vpc.ipReg] = vpc.ip
+				}
+				fmt.Print(vpc.string(), " -> ", op, " ", cmd, " -> ")
+				vpc.run(op, cmd)
+				fmt.Println(vpc.string())
+				vpc.ip = vpc.reg[vpc.ipReg]
+			}
+			vpc.ip++
+		}
+	}
+}
+
 type State struct {
 	ip, ipReg int
 	reg       [6]int
@@ -178,6 +218,25 @@ func boolToInt(v bool) int {
 	return 0
 }
 
+func getDivisors(n int) []int {
+	ret := []int{n}
+	for i := 1; i < (n / 2); i++ {
+		if n%i == 0 {
+			ret = append(ret, i)
+
+		}
+	}
+	return ret
+}
+
+func sum(vals []int) int {
+	var ret int
+	for _, v := range vals {
+		ret += v
+	}
+	return ret
+}
+
 func stdinToStringSlice() []string {
 	var input []string
 	scanner := bufio.NewScanner(os.Stdin)