Combine AoC Repos

2015/day11/main.go

@@ -0,0 +1,95 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+func printUsage() {
+	fmt.Println("Usage: day11 <string> [add-amt]")
+	fmt.Println("If add-amt isn't given, we just add 1")
+	os.Exit(1)
+}
+
+func main() {
+	args := os.Args
+	if len(args) < 2 {
+		printUsage()
+	}
+	var orig string
+	orig = args[1]
+
+	var valid bool
+	for !valid {
+		orig = addOneToString(orig)
+		valid = testPassword(orig)
+	}
+	fmt.Println(orig)
+}
+
+func addOneToString(s string) string {
+	lastPlace := s[len(s)-1]
+	ret := s[:len(s)-1]
+	if lastPlace == 'z' {
+		lastPlace = 'a'
+		ret = addOneToString(s[:len(s)-1])
+	} else {
+		lastPlace++
+	}
+	return ret + string(lastPlace)
+}
+
+func testPassword(s string) bool {
+	if hasValidChars(s) && hasStraight(s) && hasDoubles(s) {
+		return true
+	}
+	return false
+}
+
+// Test if string contains only valid chars
+func hasValidChars(s string) bool {
+	if strings.Count(s, "i") > 0 {
+		return false
+	}
+	if strings.Count(s, "o") > 0 {
+		return false
+	}
+	if strings.Count(s, "l") > 0 {
+		return false
+	}
+	return true
+}
+
+// Test if string has a 3 char straight
+func hasStraight(s string) bool {
+	for i := range s {
+		if i > 1 {
+			if (s[i-2] == s[i]-2) && (s[i-1] == s[i]-1) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// Test if string has 2 doubles
+func hasDoubles(s string) bool {
+	if i := hasDouble(s); i >= 0 {
+		return (hasDouble(s[i+2:]) >= 0)
+	}
+	return false
+}
+
+// Returns index of first double in string
+// -1 if there isn't one
+func hasDouble(s string) int {
+	for i := range s {
+		if i > 0 {
+			if s[i-1] == s[i] {
+				return i - 1
+			}
+		}
+	}
+	return -1
+}