2017 Day 15 Complete!

2017/day15/day15.go

@@ -0,0 +1,117 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"log"
+	"strconv"
+	"time"
+)
+
+var aFact, bFact int
+var doPart1, judgeIsDone bool
+var score int
+
+func main() {
+	var doPart1 bool
+	// My input
+	aStart := 679
+	bStart := 771
+	for i := range os.Args {
+		if strings.HasPrefix(os.Args[i], "-a") {
+			pts := strings.Split(os.Args[i], "=")
+			if len(pts) == 2 {
+				aStart = Atoi(pts[1])
+			}
+		} else if strings.HasPrefix(os.Args[i], "-b") {
+			pts := strings.Split(os.Args[i], "=")
+			if len(pts) == 2 {
+				bStart = Atoi(pts[1])
+			}
+		}
+		if os.Args[i] == "-test" {
+			aStart = 65
+			bStart = 8921
+		}
+		if os.Args[i] == "-1" {
+			doPart1 = true
+		}
+	}
+
+	aFact = 16807
+	bFact = 48271
+
+	if doPart1 {
+		solve(aStart, 1, bStart, 1, 40000000)
+	} else {
+		solve(aStart, 4, bStart, 8, 5000000)
+	}
+}
+
+func solve(aStart, aMod, bStart, bMod, target int) {
+	fmt.Println("= Part 2 =")
+	fmt.Print("(A ",aStart,"; B ",bStart,")\n")
+
+	judgeChanA := make(chan int)
+	judgeChanB := make(chan int)
+
+	// The Judge Process
+	go judgeWork(target, judgeChanA, judgeChanB)
+
+	// Generator A Process
+	go genWork(aStart, aFact, aMod, judgeChanA)
+	// Generator B Process
+	go genWork(bStart, bFact, bMod, judgeChanB)
+
+	// Wait for the judge to say he's done
+	for !judgeIsDone {
+		time.Sleep(500)
+	}
+	fmt.Println("\nFinal",score)
+}
+
+func judgeWork(target int, judgeChanA, judgeChanB chan int) {
+	for i := 0; i < target; i++ {
+		aVal := <-judgeChanA
+		bVal := <-judgeChanB
+		if i % (target / 25) == 0 {
+			fmt.Print(".")
+		}
+		if judge(aVal, bVal) {
+			score++
+		}
+	}
+	judgeIsDone = true
+}
+
+func genWork(start, fact, mod int, judgeChan chan int) {
+	for !judgeIsDone {
+		start = getNextVal(start, fact)
+		if start % mod == 0 {
+			judgeChan <- start
+		}
+	}
+}
+
+func getNextVal(prev, fact int) int {
+	return (prev * fact) % 2147483647
+}
+
+func judge(aVal, bVal int) bool {
+	aBin, bBin := GetBinaryString(aVal), GetBinaryString(bVal)
+	return aBin[len(aBin)-16:] == bBin[len(bBin)-16:]
+}
+
+func GetBinaryString(inp int) string {
+	return fmt.Sprintf("%032b", inp)
+}
+
+func Atoi(i string) int {
+	var ret int
+	var err error
+	if ret, err = strconv.Atoi(i); err != nil {
+		log.Fatal("Invalid Atoi")
+	}
+	return ret
+}