/**
 * Beispiele aus
 *
 * - Algorithmen und Datenstrukturen für Dummies
 *   - von Andreas Gogol-Döring und Thomas Letschert
 *   - Verlag Wiley-VCH; Oktober 2019
 *  - Kapitel 1, Das sind Algorithmen
 *
 * @author A. Gogol-Döring, Th. Letschert
 */

import Foundation

struct AuD_01_03_Riddle {

    static func Riddle(n: Int, m: Int) -> Int {
        var x = n
        var y = m
        var p = 0
        print("  n  |    m  |   x  |   y  |   p ")
        print("-----+-------+------+------+-----")
        while (x >= 1) {
            print(String(format:"%4.0d | %4.0d  | %4.0d | %4.0d | %4.0d", n, m, x, y, p))
            assert(n * m == x * y + p)
            if (x % 2 == 0) {
                x = x / 2
            } else {
                p = p + y
                x = (x - 1) / 2
            }
            y = 2 * y
        }
        print(String(format:"%4.0d | %4.0d  | %4.0d | %4.0d | %4.0d", n, m, x, y, p))
        return p
    }

    static func product(n: Int, m:Int) -> Int {
        var x = n
        var p = 0
        print( "  n  |    m  |   x  |   p ")
        print( "-----+-------+------+-----")
        while (x >= 1) {
            print(String(format:"%4.0d | %4.0d  | %4.0d | %4.0d", n, m, x, p))
            assert(n * m == x * m + p)
            p = p + m
            x = x - 1
        }
        print(String(format:"%4.0d | %4.0d  | %4.0d | %4.0d", n, m, x, p))
        return p
    }

    static func run() {
        let prod1 = product(n:5, m:6)
        print()
        let prod2 = Riddle(n:5, m:6)
        print()
        print("5*6 = \(prod1) = \(prod2)")
    }

}