Add accent vowels on input listings

Question

I'm trying to insert a C++ code inside a LaTeX document. As in the object, I'm trying to use accent vowels, but I'm not able to add them especially in the comment section. Here's main.tex:

\documentclass[a4paper, 12pt, italian]{article}
\usepackage[italian]{babel}
\selectlanguage{italian}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{listings}
\usepackage{xcolor}
\definecolor{codegreen}{rgb}{0,0.6,0}
\definecolor{codegray}{rgb}{0.5,0.5,0.5}
\definecolor{codepurple}{rgb}{0.58,0,0.82}
\definecolor{backcolour}{rgb}{0.95,0.95,0.92}
\lstdefinestyle{mystyle}{
    backgroundcolor=\color{backcolour},

    commentstyle=\color{codegreen},
    keywordstyle=\color{magenta},
    numberstyle=\tiny\color{codegray},
    stringstyle=\color{codepurple},
    basicstyle=\ttfamily\footnotesize,
    breakatwhitespace=false,

    breaklines=true,

    captionpos=b,

    keepspaces=true,

    numbers=left,

    numbersep=5pt,

    showspaces=false,

    showstringspaces=false,
    showtabs=false,

    tabsize=2
}
\lstset{style=mystyle}
\title{Casi d'uso: Prove Induttive}
\author{Luca Polese}
\date{December 2020}
\begin{document}
\maketitle
\section{Prime Prove Induttive}
\subsection{Casi semplici}
Esempio:
\lstinputlisting[language= C++]{prova1.cpp}
\end{document}

Here is prova1.cpp:

/**
 * Questo esempio deve considerare il caso in cui la lista 
 * sia già vuota in partenza.
 * Lo stessa varrebbe se cominciassi con un array pieno e mi 
 * ritrovassi ad un certo punto con un array vuoto, poichè  
 * la ricerca è fallita
 */
//PRE: (dim>=0, A[0...dim-1] è definito)
bool presente(int*A, int dim, int z){
    ...
}
//POST: (restituisce true sse A[0...dim-1] contiene z)

I'm using OverLeaf and the result is something like this:

As you can see, all the accented vowels are missing.
I hope you can help me
Thanks in advice.