Programmieren lernen

def encode(s):
    count = len(s)/2
    if (len(s) % 2):
        count+=1
    s1 = s[0:count]
    s2 = s[count:len(s)]
    out =''
    for i in range(count):
        out+=s1[i]
        if i < len(s2):
            out+=s2[i]
    return out

def decode(s):
    s1=''
    s2=''
    j=0
    while j < len(s):
        s1+=s[j]
        j+=1
        if j < len(s):
            s2+=s[j]
            j+=1
    return (s1+s2)
              
print decode(encode("1234567"))
print decode(encode("123456"))
print decode(encode("Das ist ein Test"))
                

package ch.santis.programmierenlernen.kapitel7;

public class Aufgabe_7_6 {
	
	public static void main(String[] args) {
		new Aufgabe_7_6().top();
	}
	// Geheimschrift MIX
	void top() {
		
		String text = "Geheimschrift Programm einfachb";
		
		int stringlange = text.length();
		System.out.println(stringlange);
		
		String teil1 = stringteiler1(text, stringlange);
		System.out.println(teil1);
		System.out.println(teil1.length());
		
		String teil2 = stringteiler2(text, stringlange);
		System.out.println(teil2);
		System.out.println(teil2.length());
		
		String encrypted = encription(teil1, teil2);
		System.out.println("Encrypted: " + encrypted);
		
		String decrypted = decription(encrypted);
		System.out.println("Decrypted: " + decrypted);
		
	}
	
	public String decription(String encrypted) {
		int stringlange = encrypted.length();
		
		StringBuilder sb1 = new StringBuilder();
		StringBuilder sb2 = new StringBuilder();
		String decrypted = "";
		
		for(int index = 0; index < stringlange; index++) {
			if(index % 2 == 0) {
				sb1.append(encrypted.substring(index,index+1));
			}
			else if(index % 2 == 1) {
				sb2.append(encrypted.substring(index,index+1));
			}
		}
		decrypted = sb1.toString() + sb2.toString();
		return decrypted;
	}
	
	public String encription(String teil1, String teil2){
		int teil1lange  = teil1.length();
		int teil2lange  = teil2.length();
		int stringlange = teil1lange + teil2lange;
		
		StringBuilder sb = new StringBuilder();
		String encrypted = "";
		
		int teil1counter = 0;
		int teil2counter = 0;
		for(int index = 0; index < stringlange;) {
			if(index % 2 == 1) {
				sb.append(teil2.substring(teil2counter,teil2counter+1));
				teil2counter++;
				index++;
			}
			else if(index % 2 == 0) {
				sb.append(teil1.substring(teil1counter,teil1counter+1));
				teil1counter++;
				index++;
			}
		}
		encrypted = sb.toString();
		return encrypted;
	}

	public String stringteiler1(String text, int stringlange) {
		String teil1;
		double teil1lange = (double) stringlange / 2;
		teil1lange = Math.ceil(teil1lange / 1);
		teil1 = text.substring(0, (int)teil1lange);
		return teil1;
	}
	
	public String stringteiler2(String text, int stringlange) {
		String teil2;
		double teil2lange = (double) stringlange / 2;
		teil2lange = Math.ceil(teil2lange / 1);
		teil2 = text.substring( (int)teil2lange, stringlange);
		return teil2;
	}
	
}
                

Lösung von: Jan Roth (Santis Training AG)

codeMIX = {
  encode: function(str) {
    let mid = Math.ceil(str.length / 2),
        sub1 = str.substr(0, mid),
        sub2 = str.substr(mid),
        out = '';
    for (let i = 0; i < sub1.length; i++) {
      out += sub1[i];
      if (i < sub2.length) out += sub2[i];
    }
    return out;
  },
  decode: function(str) {
    let out = '';
    for (let i = 0; i < str.length; i += 2)
      out += str[i];
    for (let i = 1; i < str.length; i += 2)
      out += str[i];
    return out;
  }
}

console.log(codeMIX.encode('strenggeheim'));
console.log(codeMIX.decode(codeMIX.encode('strenggeheim')));
                                                             // lissalanda@gmx.at
                

Lösung von: Lisa Salander (Heidi-Klum-Gymnasium Bottrop)

# frozen_string_literal: false

def mix(data = '')
  len = data.length
  if (len % 2).zero?
    str1 = data[0..((len / 2) - 1)]
    str2 = data[(len / 2)..len]
  else
    str1 = data[0..(len / 2)]
    str2 = data[((len + 1) / 2)..len] + ' '
  end

  mixed = ''

  (0..(str1.length - 1)).each do |i|
    mixed += str1[i]
    mixed += str2[i]
  end
  mixed[0..(mixed.length - 2)]
end

def demix(data = '')
  str1 = ''
  str2 = ''

  (0..(data.length - 1)).step(2).each do |i|
    str1 += data[i] if data[i]
    str2 += data[i + 1] if data[i + 1]
  end

  str1 + str2
end

a = mix('Streng geheim')
puts 'codiert: ' << a
b = demix(a)
puts 'wieder decodiert: ' << b

puts 'Vorgabe per Mix "decodiert":'
c = mix('Srn eemtegghi')
puts '"decodiert": ' << c

                

Lösung von: Ich Bins (tubs)

import math
from itertools import zip_longest

def encode(s):
    l = math.ceil(len(s)/2)
    a, b, out = s[:l], s[l:], ""
    for x in zip_longest(a, b, fillvalue=""):
        out += "".join(x)
    return out

def decode(s):
    a, b = "", ""
    for i in range(len(s)):
        if i % 2 == 0:
            a += s[i]
        else:
            b += s[i]
    return a+b

s = input("Input: ")
print(f"Encode: {encode(s)}")
print(f"Decode: {decode(s)}")
                

Lösung von: Name nicht veröffentlicht

// C++ 14 | VS-2022
#include <iostream>
#include <string>

std::string encode_text(const std::string& str) {
	std::string out{};
	auto odd{ str.length() / 2 + (str.length() & 1 ? 1 : 0) };
	for (size_t i{ 0 }; i < odd; i++) {
		out.push_back(str[i]);
		out.push_back(str[i + odd]);
	}
	if (str.length() & 1) out.push_back(str.back());
	return out;
}

std::string decode_text(const std::string& str) {
	std::string t1, t2;
	for (size_t i{ 0 }; i < str.length(); i+=2) {
		t1.push_back(str[i]);
		t2.push_back(str[i + 1]);
	}
	return t1.append(t2);
}

int main() {
	const auto s1{ "streng_geheim" };
    std::cout << encode_text(s1) << "\n";

	const auto s2{ "sgterheenigm_" };
	std::cout << decode_text(s2) << "\n";
}
                

Lösung von: Jens Kelm (@JKooP)