declare const PR: any;

ngAfterViewChecked() {
    PR.prettyPrint();
}

li.L0, li.L1, li.L2, li.L3,
li.L5, li.L6, li.L7, li.L8 {
    list-style-type: decimal !important;
}

pre.prettyprint {
    border-radius: 0;
    white-space: pre;
}

<pre class="prettyprint linenums lang-cpp">
...
Place the code here
...
</pre>