// exercise01
{
  let p = document.querySelector("p");
  p.innerHTML = ((__rkt_body) => {
    const __rkt_to_regexp = (__pat, __global) => {
      const __flags = (__pat instanceof RegExp)
        ? Array.from(new Set((__pat.flags.replace(/g/g, '') + (__global ? 'g' : '')).split(''))).join('')
        : (__global ? 'g' : '');
      return (__pat instanceof RegExp) ? new RegExp(__pat.source, __flags) : new RegExp(String(__pat), __flags);
    };
    const __rkt_match_array = (__m) => (__m === null ? false : Array.from(__m, (__x) => __x === undefined ? false : __x));
    const __rkt_replacement = (__s) => {
      if (typeof __s !== 'string') return __s;
      let __out = '';
      for (let __i = 0; __i < __s.length; __i++) {
        const __ch = __s[__i];
        if (__ch === '$') { __out += '$$'; continue; }
        if (__ch === '\\' && __i + 1 < __s.length) {
          const __n = __s[++__i];
          if (__n >= '0' && __n <= '9') __out += (__n === '0' ? '$&' : ('$' + __n));
          else __out += __n;
        } else __out += __ch;
      }
      return __out;
    };
    return __rkt_body(__rkt_to_regexp, __rkt_match_array, __rkt_replacement);
  })((__rkt_to_regexp, __rkt_match_array, __rkt_replacement) => String(p.innerHTML).replace(__rkt_to_regexp(new RegExp("\\b\\w{9,}\\b"), true), __rkt_replacement(function(word) {
    return ("<span style=\"background: yellow\">" + word + "</span>");
  })));
}

// exercise02
{
  let p = document.querySelector("p");
  p.insertAdjacentHTML("afterend", "<a href=\"https://forcemipsum.com/\">Source: ForceM Ipsum</a>");
}

// exercise03
{
  let p = document.querySelector("p");
  p.innerHTML = ((__rkt_body) => {
    const __rkt_to_regexp = (__pat, __global) => {
      const __flags = (__pat instanceof RegExp)
        ? Array.from(new Set((__pat.flags.replace(/g/g, '') + (__global ? 'g' : '')).split(''))).join('')
        : (__global ? 'g' : '');
      return (__pat instanceof RegExp) ? new RegExp(__pat.source, __flags) : new RegExp(String(__pat), __flags);
    };
    const __rkt_match_array = (__m) => (__m === null ? false : Array.from(__m, (__x) => __x === undefined ? false : __x));
    const __rkt_replacement = (__s) => {
      if (typeof __s !== 'string') return __s;
      let __out = '';
      for (let __i = 0; __i < __s.length; __i++) {
        const __ch = __s[__i];
        if (__ch === '$') { __out += '$$'; continue; }
        if (__ch === '\\' && __i + 1 < __s.length) {
          const __n = __s[++__i];
          if (__n >= '0' && __n <= '9') __out += (__n === '0' ? '$&' : ('$' + __n));
          else __out += __n;
        } else __out += __ch;
      }
      return __out;
    };
    return __rkt_body(__rkt_to_regexp, __rkt_match_array, __rkt_replacement);
  })((__rkt_to_regexp, __rkt_match_array, __rkt_replacement) => String(p.textContent).replace(__rkt_to_regexp(new RegExp("\\.\\s*"), true), __rkt_replacement(".<br>")));
}

// exercise04
{
  let heading = document.querySelector("h1");
  let p = document.querySelector("p");
  let words = ((__rkt_body) => {
    const __rkt_to_regexp = (__pat, __global) => {
      const __flags = (__pat instanceof RegExp)
        ? Array.from(new Set((__pat.flags.replace(/g/g, '') + (__global ? 'g' : '')).split(''))).join('')
        : (__global ? 'g' : '');
      return (__pat instanceof RegExp) ? new RegExp(__pat.source, __flags) : new RegExp(String(__pat), __flags);
    };
    const __rkt_match_array = (__m) => (__m === null ? false : Array.from(__m, (__x) => __x === undefined ? false : __x));
    const __rkt_replacement = (__s) => {
      if (typeof __s !== 'string') return __s;
      let __out = '';
      for (let __i = 0; __i < __s.length; __i++) {
        const __ch = __s[__i];
        if (__ch === '$') { __out += '$$'; continue; }
        if (__ch === '\\' && __i + 1 < __s.length) {
          const __n = __s[++__i];
          if (__n >= '0' && __n <= '9') __out += (__n === '0' ? '$&' : ('$' + __n));
          else __out += __n;
        } else __out += __ch;
      }
      return __out;
    };
    return __rkt_body(__rkt_to_regexp, __rkt_match_array, __rkt_replacement);
  })((__rkt_to_regexp, __rkt_match_array, __rkt_replacement) => String(p.textContent).split(__rkt_to_regexp(new RegExp(" "), true)));
  let count = (words).length;
  heading.insertAdjacentHTML("afterend", ("<p>" + String(count) + " words</p>"));
}

// exercise05
{
  let p = document.querySelector("p");
  let step = ((__rkt_body) => {
    const __rkt_to_regexp = (__pat, __global) => {
      const __flags = (__pat instanceof RegExp)
        ? Array.from(new Set((__pat.flags.replace(/g/g, '') + (__global ? 'g' : '')).split(''))).join('')
        : (__global ? 'g' : '');
      return (__pat instanceof RegExp) ? new RegExp(__pat.source, __flags) : new RegExp(String(__pat), __flags);
    };
    const __rkt_match_array = (__m) => (__m === null ? false : Array.from(__m, (__x) => __x === undefined ? false : __x));
    const __rkt_replacement = (__s) => {
      if (typeof __s !== 'string') return __s;
      let __out = '';
      for (let __i = 0; __i < __s.length; __i++) {
        const __ch = __s[__i];
        if (__ch === '$') { __out += '$$'; continue; }
        if (__ch === '\\' && __i + 1 < __s.length) {
          const __n = __s[++__i];
          if (__n >= '0' && __n <= '9') __out += (__n === '0' ? '$&' : ('$' + __n));
          else __out += __n;
        } else __out += __ch;
      }
      return __out;
    };
    return __rkt_body(__rkt_to_regexp, __rkt_match_array, __rkt_replacement);
  })((__rkt_to_regexp, __rkt_match_array, __rkt_replacement) => String(p.innerHTML).replace(__rkt_to_regexp(new RegExp("\\?"), true), __rkt_replacement("🤔")));
  let out = ((__rkt_body) => {
    const __rkt_to_regexp = (__pat, __global) => {
      const __flags = (__pat instanceof RegExp)
        ? Array.from(new Set((__pat.flags.replace(/g/g, '') + (__global ? 'g' : '')).split(''))).join('')
        : (__global ? 'g' : '');
      return (__pat instanceof RegExp) ? new RegExp(__pat.source, __flags) : new RegExp(String(__pat), __flags);
    };
    const __rkt_match_array = (__m) => (__m === null ? false : Array.from(__m, (__x) => __x === undefined ? false : __x));
    const __rkt_replacement = (__s) => {
      if (typeof __s !== 'string') return __s;
      let __out = '';
      for (let __i = 0; __i < __s.length; __i++) {
        const __ch = __s[__i];
        if (__ch === '$') { __out += '$$'; continue; }
        if (__ch === '\\' && __i + 1 < __s.length) {
          const __n = __s[++__i];
          if (__n >= '0' && __n <= '9') __out += (__n === '0' ? '$&' : ('$' + __n));
          else __out += __n;
        } else __out += __ch;
      }
      return __out;
    };
    return __rkt_body(__rkt_to_regexp, __rkt_match_array, __rkt_replacement);
  })((__rkt_to_regexp, __rkt_match_array, __rkt_replacement) => String(step).replace(__rkt_to_regexp(new RegExp("!"), true), __rkt_replacement("😲")));
  p.innerHTML = out;
}