Change my code, so that it doesn$$t bring any error when I compile it with g$++$ compiler. Also, I want my code to be in a C programming language format as much as possible. Here is my code about distance vector:

#include

#include

#include

#define MAX$\_$NODES $100$

#define INFINITY $999999$

typedef struct $\{$

int cost$[$MAX$\_$NODES$]$;

int next$\_$hop$[$MAX$\_$NODES$]$;

$\}$ RoutingTable;

int num$\_$nodes;

int graph$[$MAX$\_$NODES$][$MAX$\_$NODES$]$;

RoutingTable rt$[$MAX$\_$NODES$]$;

void read$\_$topology$($const char $*$filename$)\{$

FILE $*$file $=$ fopen$($filename$,"$r$")$;

if $(!$file$)\{$

printf$("$Error: open input file.

$")$;

exit$(1)$;

$\}$

fscanf$($file$,"\%$d$",$ &num$\_$nodes$)$;

for $($int i $=0$; i $<$ num$\_$nodes; i$++)\{$

for $($int j $=0$; j $<$ num$\_$nodes; j$++)\{$

if $($i $==$ j$)\{$

graph$[$i$][$j$]=0$;

$\}$ else $\{$

graph$[$i$][$j$]=$ INFINITY;

$\}$

$\}$

$\}$

int node$1,$ node$2,$ cost;

while $($fscanf$($file$,"\%$d $\%$d $\%$d$",$ &node$1,$ &node$2,$ &cost$)!=$ EOF$)\{$

graph$[$node$1][$node$2]=$ cost;

graph$[$node$2][$node$1]=$ cost;

$\}$

fclose$($file$)$;

$\}$

void initialize$\_$routing$\_$table$()\{$

for $($int i $=0$; i $<$ num$\_$nodes; i$++)\{$

for $($int j $=0$; j $<$ num$\_$nodes; j$++)\{$

if $($i $==$ j$)\{$

rt$[$i$].$cost$[$j$]=0$;

rt$[$i$].$next$\_$hop$[$j$]=$ i;

$\}$ else if $($graph$[$i$][$j$]!=$ INFINITY$)\{$

rt$[$i$].$cost$[$j$]=$ graph$[$i$][$j$]$;

rt$[$i$].$next$\_$hop$[$j$]=$ j;

$\}$ else $\{$

rt$[$i$].$cost$[$j$]=$ INFINITY;

rt$[$i$].$next$\_$hop$[$j$]=-1$;

$\}$

$\}$

$\}$

$\}$

void update$\_$routing$\_$table$()\{$

int updated;

do $\{$

updated $=0$;

for $($int i $=0$; i $<$ num$\_$nodes; i$++)\{$

for $($int j $=0$; j $<$ num$\_$nodes; j$++)\{$

for $($int k $=0$; k $<$ num$\_$nodes; k$++)\{$

if $($rt$[$i$].$cost$[$j$]>$ rt$[$i$].$cost$[$k$]+$ rt$[$k$].$cost$[$j$])\{$

rt$[$i$].$cost$[$j$]=$ rt$[$i$].$cost$[$k$]+$ rt$[$k$].$cost$[$j$]$;

rt$[$i$].$next$\_$hop$[$j$]=$ rt$[$i$].$next$\_$hop$[$k$]$;

updated $=1$;

$\}$

$\}$

$\}$

$\}$

$\}$ while $($updated$)$;

$\}$

void print$\_$routing$\_$table$($FILE $*$output$,$ int src$)\{$

for $($int i $=0$; i $<$ num$\_$nodes; i$++)\{$

fprintf$($output$,"\%$d $\%$d $\%$d

$",$ i$,$ rt$[$src$].$next$\_$hop$[$i$],$ rt$[$src$].$cost$[$i$])$;

$\}$

fprintf$($output$,"$

$")$;

$\}$

void read$\_$messages$($const char $*$filename$,$ FILE $*$output$)\{$

FILE $*$file $=$ fopen$($filename$,"$r$")$;

if $(!$file$)\{$

printf$("$Error: open input file.

$")$;

exit$(1)$;

$\}$

int src$,$ dst;

char message$[1000]$;

while $($fscanf$($file$,"\%$d $\%$d$",$ &src$,$ &dst$)!=$ EOF$)\{$

fgets$($message$,$ sizeof$($message$),$ file$)$;

message$[$strlen$($message$)-1]=\text{'}\backslash 0\text{'}$; $//$ Remove newline character

if $($rt$[$src$].$cost$[$dst$]==$ INFINITY$)\{$

fprintf$($output$,$ "from $\%$d to $\%$d cost infinite hops unreachable message $\%$s

$",$ src$,$ dst$,$ message$)$;

$\}$ else $\{$

fprintf$($output$,$ "from $\%$d to $\%$d cost $\%$d hops", src$,$ dst$,$ rt$[$src$].$cost$[$dst$])$;

int hop $=$ src;

while $($hop $!=$ dst$)\{$

fprintf$($output$,"\%$d$",$ hop$)$;

hop $=$ rt$[$hop$].$next$\_$hop$[$dst$]$;

$\}$

fprintf$($output$,"$ message $\%$s

$",$ message$)$;

$\}$

$\}$

fclose$($file$)$;

$\}$

void apply$\_$changes$($const char $*$filename$)\{$

FILE $*$file $=$ fopen$($filename$,"$r$")$;

if $(!$file$)\{$

printf$("$Error: open input file.

$")$;

exit$(1)$;

$\}$

int node$1,$ node$2,$ cost;

while $($fscanf$($file$,"\%$d $\%$d $\%$d$",$ &node$1,$ &node$2,$ &cost$)!=$ EOF$)\{$

if $($cost $==-999)\{$

graph$[$node$1][$node$2]=$ INFINITY;

graph$[$node$2][$node$1]=$ INFINITY;

$\}$ else $\{$

graph$[$node$1][$node$2]=$ cost;

graph$[$node$2][$node$1]=$ cost;

$\}$

$\}$

fclose$($file$)$;

$\}$

int main$($int argc, char $*$argv$[])\{$

if $($argc $!=4)\{$

printf$("$usage: distvec topologyfile messagesfile changesfile

$")$;

return $1$;

$\}$

read$\_$topology$($argv$[1])$;

FILE $*$output $=$ fopen$("$output$\_$dv$.$txt$","$w$")$;

if $(!$output$)\{$

printf$("$Error: open output file.

$")$;

return $1$;

$\}$

initialize$\_$routing$\_$table$()$;

update$\_$routing$\_$table$()$;

for $($int i $=0$; i $<$ num$\_$nodes; i$++)\{$

print$\_$routing$\_$table$($output$,$ i$)$;

$\}$

read$\_$messages$($argv$[2],$ output$)$;

apply$\_$changes$($argv$[3])$;

initialize$\_$routing$\_$table$()$;

update$\_$routing$\_$table$()$;

for $($int i $=0$; i $<$ num$\_$nodes; i$++)\{$

print$\_$routing$\_$table$($output$,$ i$)$;

$\}$

read$\_$messages$($argv$[2],$ output$)$;

fclose$($output$)$;

printf$("$Complete$.$ Output file written to output$\_$dv$.$txt$.$

$")$;

return $0$;

$\}$