What is wrong with the following latex code? [closed]

Question

I have written this code to formulate the algorithm for merging two arrays, but I get an error.

\begin{algorithm}[t]
\caption{Serial Merge}
\label{alg:insert}
\begin{algorithmic}[1]
\Require Two sorted arrays $A$ and $B$
\Ensure Sorted Array $C$
\State $lA \leftarrow length(A)$
\State $lB \leftarrow length(B)$
\State $x \leftarrow 0$
\State $y \leftarrow 0$
\State $z \leftarrow 0$

 \While { $x \neq lA$ and $y \neq lB$ }
 \If { $A[x] < $B[y]$}
    \State $C[z++] \leftarrow A[x++]$
  \Else
        \State $C[z++] \leftarrow B[y++]$
    \EndIf
\EndWhile

\While { $x \neq lA$ }
    \State $C[z++] \leftarrow A[x++]$
\EndWhile

\While { $y \neq lB$ }
    \State $C[z++] \leftarrow B[y++]$
\EndWhile

\end{algorithmic}
\end{algorithm}

Error:

! LaTeX Error: Command \item invalid in math mode.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.15     \State
                $C[z++] \leftarrow A[x++]$
? 

It works if I remove the surrounding if else statements. What am I doing wrong?

Answer 1

In the line

\If { $A[x] < $B[y]$}

there's a spurious $ character before the "B"; simply delete it:

\documentclass{article}
\usepackage{algorithm}
\usepackage{algpseudocode}

\begin{document}

\begin{algorithm}%[t]
\caption{Serial Merge}
\label{alg:insert}
\begin{algorithmic}[1]
\Require Two sorted arrays $A$ and $B$
\Ensure Sorted Array $C$
\State $lA \leftarrow length(A)$
\State $lB \leftarrow length(B)$
\State $x \leftarrow 0$
\State $y \leftarrow 0$
\State $z \leftarrow 0$
%
 \While { $x \neq lA$ and $y \neq lB$ }
 \If { $A[x] < B[y]$}
    \State $C[z++] \leftarrow A[x++]$
  \Else
        \State $C[z++] \leftarrow B[y++]$
    \EndIf
\EndWhile
%
\While { $x \neq lA$ }
    \State $C[z++] \leftarrow A[x++]$
\EndWhile
%
\While { $y \neq lB$ }
    \State $C[z++] \leftarrow B[y++]$
\EndWhile
\end{algorithmic}
\end{algorithm}

\end{document}