initial commit

main.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+// NICHT FÜR MULTITHREADING GEEIGNET :(
+
+func main() {
+	fmt.Printf("%d", findNumberByBouncyPercentage(0.99))
+
+}
+
+func returnDigit(num, place int) int {
+	r := num % int(math.Pow(10, float64(place)))
+	return r / int(math.Pow(10, float64(place-1)))
+}
+
+func countDigits(num int) (count int) {
+	for num != 0 {
+		num /= 10
+		count = count + 1
+	}
+	return count
+}
+
+func isBouncy(num int) bool {
+	var isIncreasing = true
+	var isDecreasing = true
+	for i := countDigits(num); i > 1; i-- {
+		if returnDigit(num, i) < returnDigit(num, i-1) {
+			isDecreasing = false
+		} else {
+			if returnDigit(num, i) > returnDigit(num, i-1) {
+				isIncreasing = false
+			}
+		}
+		if !(isIncreasing || isDecreasing) {
+			return true
+		}
+	}
+	return false
+}
+
+func findNumberByBouncyPercentage(percentage float64) (num int) {
+	num = 1
+	var bouncyCount = 0
+	for {
+		if isBouncy(num) {
+			bouncyCount++
+		}
+		var proportion = float64(bouncyCount) / float64(num)
+		if proportion == percentage {
+			return num
+		} else if proportion > percentage || percentage >= 1 {
+			fmt.Printf("no number at which the bouncy proportion is exactly %d could be found", percentage)
+			return num
+		}
+		num++
+	}
+}