148 lines
2.9 KiB
Go
148 lines
2.9 KiB
Go
package utils
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/*
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In Golang sind manche (basic!) mathematischen Vorgänge etwas umständlich zu implementieren.
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Wir wollen diese Methoden komplett einhüllen, damit wir von ihrer Komplexität
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in den Algorithmen nicht abgelenkt werden.
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*/
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/* ---------------------------------------------------------------- *
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* IMPORTS
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* ---------------------------------------------------------------- */
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import (
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"fmt"
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"math"
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"strconv"
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)
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/* ---------------------------------------------------------------- *
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* METHOD floor, ceil
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* ---------------------------------------------------------------- */
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func Floor(x float64) int {
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return int(math.Floor(x))
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}
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func Ceil(x float64) int {
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return int(math.Ceil(x))
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}
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/* ---------------------------------------------------------------- *
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* METHOD max, min
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* ---------------------------------------------------------------- */
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func MinInt(x int, y ...int) int {
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if len(y) == 0 {
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return x
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} else if x < y[0] {
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return MinInt(x, y[1:]...)
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} else {
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return MinInt(y[0], y[1:]...)
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}
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}
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func MaxInt(x int, y ...int) int {
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if len(y) == 0 {
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return x
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} else if x > y[0] {
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return MaxInt(x, y[1:]...)
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} else {
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return MaxInt(y[0], y[1:]...)
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}
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}
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func ArgMinInt(X []int) int {
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if len(X) == 0 {
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return -1
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}
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minValue := X[0]
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index := 0
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for i, x := range X {
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if x < minValue {
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minValue = x
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index = i
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}
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}
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return index
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}
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func ArgMaxInt(X []int) int {
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if len(X) == 0 {
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return -1
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}
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maxValue := X[0]
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index := 0
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for i, x := range X {
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if x > maxValue {
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maxValue = x
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index = i
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}
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}
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return index
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}
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/* ---------------------------------------------------------------- *
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* METHOD sum
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* ---------------------------------------------------------------- */
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func SumListInt(X []int) int {
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result := 0
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for _, x := range X {
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result += x
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}
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return result
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}
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func SumListFloat(X []float64) float64 {
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result := 0.
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for _, x := range X {
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result += x
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}
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return result
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}
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/* ---------------------------------------------------------------- *
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* METHODS binary
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* ---------------------------------------------------------------- */
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/*
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Für eine Zahl n != 0 liefert die Länge der binären Darstellung der Zahl,
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und für n == 0 liefert 0
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*/
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func LengthOfBinary(number int) int {
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if number == 0 {
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return 0
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}
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if number < 0 {
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number = -number
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}
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number_binary := fmt.Sprintf("%b", int64(number))
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return len([]rune(number_binary))
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}
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/*
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Für eine Zahl n != 0 liefert die Bits der binären Darstellung
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*/
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func IntToBinary(number int) []int {
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if number == 0 || number == 1 {
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return []int{number}
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}
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number_binary := fmt.Sprintf("%b", int64(number))
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runes := []rune(number_binary)
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bits := make([]int, len(runes))
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for i, rune := range runes {
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bit, _ := strconv.ParseInt(fmt.Sprintf("%c", rune), 2, 64)
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bits[len(runes)-1-i] = int(bit)
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}
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return bits
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}
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func NthBit(number int, digit int) int {
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bits := IntToBinary(number)
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if digit < len(bits) {
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return bits[digit]
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}
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return 0
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}
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