How do I draw this picture of boxes with arrows in LaTeX?

Question

I need it to look exactly like this:

This is how far I got, but I’m stuck:

\documentclass[10pt, a4paper] {article}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{amsmath,amssymb}
\usepackage{graphicx}
\usepackage{hyperref}
\usepackage [Symbol]{upgreek}
\usepackage{tikz}

\begin{document}
\begin{figure}[!htb]
    \begin{tikzpicture}
    \draw[ultra thick] [ | ->] (0,4.4) --(3,4.4)
    \draw[fill=white] (4,4) rectangle (5,5);
    \begin{scope}[xshift=-1cm] \draw [fill=white] (4,4) rectangle (5,5);
    \end{scope}
    \end{tikzpicture}
    \end{figure}
\end{document}

Answer 1

This is to give you a welcome.

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{shapes.multipart,chains}
\begin{document}
\begin{tikzpicture}[mp/.style args={#1/#2}{rectangle split,rectangle split horizontal,
rectangle split parts=2,text width=2em,align=center,minimum height=2.2em,
on chain,draw,node contents={#1\nodepart[text width=3em]{two}#2}}]
 \begin{scope}[start chain=going right,node distance=4em]
  \node[on chain](C) {C};
  \node (A1)[mp=4/~];
  \node (A2)[mp=4/~];
  \node (A3)[mp=6/Nil];
 \end{scope}
 \draw[very thick,|-latex] (C) -- (A1); 
 \foreach \X in {1,2}
 {\draw[very thick,|-latex] (A\X.two north|-A\X) -- (A\the\numexpr\X+1);}
\end{tikzpicture}
\end{document}

For the future, please always post the code that you have tried, never use screen shots (or do you really expect others to punch in the text from these), nor links to codes (because these links may die, and it is generally not a good idea to follow random links on the internet). Also your screen shot depicts a code fragment. However, it is expected that one posts complete documents that start with \documentclass, end with \end{document}, are as minimal as possible, and can be compiled.

And here is an annotated version. Clearly, annotations won't be as detailed as the manual.

\documentclass[tikz,border=3mm]{standalone}
% we load two libraries. shapes.multipart allows us to draw partitioned boxes
% and chains makes it possible to place nodes along chains 
\usetikzlibrary{shapes.multipart,chains}
\begin{document}
\begin{tikzpicture}[mp/.style args={#1/#2}{ %<- defines a style that takes 2 args
    rectangle split,%<- we want a partitioned rectangle
    rectangle split horizontal,%<- the partitions should be horizontal
    rectangle split parts=2,%<- two partitions, please
    text width=2em,%<- overall text width (we will change the second one
    align=center,%<- texts should be centered
    minimum height=2.2em,%<- selfexplantory
    on chain,%<- puts them on the chain
    draw,%<- draw node boundaries
    node contents={#1\nodepart[text width=3em]{two}#2}}
    ]% ^ here we specify how the arguments are to be used
    % whatever is before the / will go in the first part, 
    % what comes after in the second
 \begin{scope}[start chain=going right,% start a chain growing to the right
    node distance=4em]% distance between nodes 
  \node[on chain](C) {C};
  \node (A1)[mp=4/~]; %<- use the mp style to create a node of name A1
        % with first part 4 and second part just a space (standard trick)
  \node (A2)[mp=4/~];
  \node (A3)[mp=6/Nil];
 \end{scope}
 \draw[very thick,|-latex] (C) -- (A1); 
 \foreach \X in {1,2}
 {\draw[very thick,|-latex] (A\X.two north|-A\X) -- (A\the\numexpr\X+1);
  % ^ draws the arrow from the center of the right partition of node \X
  % to node \X+1 (we need to evaluate \X+1, hence \the\numexpr)
 }
\end{tikzpicture}
\end{document}

ADDENDUM: An extended comment/reply to lucky1928, who suggested to use join. It is a great idea but some extra treatment has to be applied to the first node.

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{shapes.multipart,chains}
\begin{document}
\begin{tikzpicture}[mp/.style args={#1/#2}{rectangle split,rectangle split horizontal,
rectangle split parts=2,text width=2em,align=center,minimum height=2.2em,
on chain,draw,join,node contents={#1\nodepart[text width=3em]{two}#2}}]
 \begin{scope}[start chain=going right,node distance=4em,
 every join/.style={very thick,|-latex,to path={(\tikztostart.two north|-\tikztostart) -- (\tikztotarget)}}]
  \node[on chain,rectangle split,rectangle split horizontal,
    rectangle split parts=2,inner xsep=0.5pt](C) {C};
  \node (A1)[mp=4/~];
  \node (A2)[mp=4/~];
  \node (A3)[mp=6/Nil];
 \end{scope}
\end{tikzpicture}
\end{document}

Answer 2

And just so you know that you don't have to use TikZ, here's an alternative in Metapost. You will need to compile this example with the lualatex version of TeX.

\documentclass[border=5mm]{standalone}
\usepackage{luatex85}
\usepackage{luamplib}
\begin{document}
\mplibtextextlabel{enable}
\begin{mplibcode}
def drawtailarrow expr p = _apth := p; _fintarr enddef;
def _fintarr text t =
  draw (up--down) scaled 3 shifted point 0 of _apth t;
  draw _apth t;
  filldraw arrowhead _apth t
enddef;
beginfig(1);
    numeric ht, wd; ht = 21; wd = 34;

    path box[];
    box1 = unitsquare xscaled wd yscaled ht;
    box3 = box1 shifted (3 wd, 0);
    box5 = box1 shifted (6 wd, 0);

    box2 = unitsquare scaled ht shifted point 1 of box1;
    box4 = unitsquare scaled ht shifted point 1 of box3;
    box6 = unitsquare scaled ht shifted point 1 of box5;

    z0 = center box1 shifted (-3/2 wd, 0);
    label("$C$", z0);
    label("$4$", center box1);
    label("$6$", center box3);
    label("$6$", center box5);
    label("Nil", center box6);

    forsuffixes $=1,2,3,4,5,6: draw box$ withcolor 3/4 blue; endfor

    interim linecap := 0;  % these parameters improve the look of 
    interim linejoin := 0; % the arrows drawn with a fat pen
    interim ahangle := 30;

    drawoptions(withpen pencircle scaled 1.2 withcolor 2/3 red);
    drawtailarrow z0 shifted 10 right -- point 7/2 of box1;
    drawtailarrow center box2 -- point 7/2 of box3;
    drawtailarrow center box4 -- point 7/2 of box5;
    drawoptions();

endfig;
\end{mplibcode}
\end{document}

Answer 3

Here is a way with pstricks:

\documentclass{article}
\usepackage{geometry}
\usepackage{array, bigstrut}
\newcommand{\mybox}[1]{%
\setlength{\bigstrutjot}{1.5ex}
\begin{tabular}{|>{\centering}p{3em}|>{\centering\arraybackslash}p{1.6em}|}%
\hline
\bigstrut #1 \tabularnewline
\hline
\end{tabular}
}%

\usepackage{pst-node, pst-arrow, auto-pst-pdf}

\begin{document}

\begin{psmatrix}[colsep=1.2cm]
  [name =C]C &\mybox{4 & \pnode[0, 0.7ex]{A}} & \mybox{ 6 & \pnode[0, 0.7ex]{B}} & \mybox{ 6 & Nil}
\psset{linewidth=1.33pt, arrows=|-v, veearrowangle=60, veearrowlength=2mm, veearrowlinewidth=1.33pt, linejoin=1, nodesepB=-2.67pt}
\ncline[nodesepA=0.75em]{C}{1,2}\ncline{A}{1,3}\ncline{B}{1,4}
\end{psmatrix}

\end{document}