    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Problem: Given a string, replace all spaces with '%20', in-place\n",
      "\n",
      "* [Constraints](#Constraints)\n",
      "* [Test Cases](#Test-Cases)\n",
      "* [Algorithm](#Algorithm)\n",
      "* [Code](#Code)\n",
 
</s> remove     "## Problem: Given a string, replace in-place all spaces with '%20'\n",
 </s> add     "## Problem: Given a string (a list of characters), replace in-place all spaces with '%20'\n", </s> remove     "* Since Python strings are immutable and we are asked to do this in-place, can I use a bytearray or a list instead?\n",
 </s> add     "* Since Python strings are immutable and we are asked to do this in-place, can I use a list or a bytearray instead?\n",
    "## Problem: Given a string (a list of characters), replace all spaces with '%20', in-place\n",
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
    "## Problem: Given a string (a list of characters), replace all spaces with '%20', in-place\n",
      "\n",
      "* [Constraints](#Constraints)\n",
      "* [Test Cases](#Test-Cases)\n",
      "* [Algorithm](#Algorithm)\n",
      "* [Code](#Code)\n",
keep keep keep keep replace keep keep keep keep keep
 Tweaked replace char challenge problem statement and contraints. 
arrays_strings/replace_char/replace_char_challenge.ipynb