void setup() {
  size(600, 600);
  fill(0);  

  // 1. populate an array with random characters
  int num = 10;
  char[] chars = populate(num);
  
  // 2. render characters
  renderChars(chars);
  
  // 3. get a reversed string
  String rev = combine(chars);
  renderString(rev);
  
  // 4. shuffle initial array
  char[] rchars = randomise(chars);
  renderChars2(rchars); 

  save("assignment7.png");
}

char[] populate(int num) {
  char[] chars = new char[num];
  for(int i=0; i < num; i++) {
    char c = (char)random(97,122);
    chars[i] = c;
    print(c);
  }
  
  return chars;
}

void renderChars(char[] chars) {
  fill(0);
  textSize(16);
  text("1. Rendering " + chars.length + " random characters: ", 20, 70);
  for(int i=0; i < chars.length; i++) {
    text(chars[i], 20 + (i*10), 100);
  }
}

String combine(char[] chars) {
  String s = "";
  for(int i=chars.length - 1; i >= 0; i--) {
    s += chars[i] + " ";
  }
  
  return s;
}

void renderString(String s) {
  fill(0);
  textSize(16);
  text("2. Rendering reversed string: ", 20, 140);
  text(s, 20 , 170);
}

char[] randomise(char[] chars) {
  char[] rchars = new char[chars.length];
  
  for(int i=0; i < chars.length; i++) {
    int j = (int)random(0, chars.length);
    char c = rchars[j];  

    while(c != '\u0000') {
      j = (int)random(0, chars.length);
      c = rchars[j];
    }

    rchars[j] = chars[i];
  }
  
  return rchars;
}

void renderChars2(char[] chars) {
  fill(0);
  textSize(16);
  text("3. Rendering with random order: ", 20, 210);
  for(int i=0; i < chars.length; i++) {
    text(chars[i], 20 + (i*10), 240);
  }
}