this code you guys gave me doesn't work: #include Imagine there is an "unknown" data structure that holds a collection of strings. It has two operations defined as follows:

How this data structure works is mysterious. Given a sequence of operations, it may operate like a LIFO stack, or it may not.

Your program must determine whether or not it is operating as a stack given a series of operations and the corresponding returned strings.

Program Input and Output

Input File Format

length of $10.$ The input is terminated by reaching end$-$of$-$file $($EOF$).$

program. You can also use the Stack.h template in this module.

Program Output

For each test case, output one of these lines:

stack

not stack

which will indicate whether or not the series of operations are behaving like a stack $($in LIFO order$).$

Sample Input

Create a text file with the following lines and use it as input into your program.

$4$

i cat

i dog

r dog

r$\}\backslash$mathrm$\{$ cat

$6$

sunshine

i apple

i street

r apple

r street

r$\}\backslash$mathrm$\{$ sunshine

$2$

red

red

i blue

i green

r green Sample Output

When your program reads the above input file, it should output these four lines only:

stack

not stack

stack

not stack

Explanation of the Sample Output

output:

st

most recent string inserted$).$ At that point we know that this is not a stack, so program outputs:

no

At this point your code can skip the remaining lines in that test case and proceed to the next one in the file.

The fourth case inserts two strings, then removes one in the correct order $(\text{'}$green$\text{'}$ comes out first$).$ The test case ends and the stack is not empty, so the program outputs:

hot stack Imagine there is an "unknown" data structure that holds a collection of strings. It has two operations defined as follows:

How this data structure works is mysterious. Given a sequence of operations, it may operate like a LIFO stack, or it may not.

Your program must determine whether or not it is operating as a stack given a series of operations and the corresponding returned strings.

Program Input and Output

Input File Format

length of $10.$ The input is terminated by reaching end$-$of$-$file $($EOF$).$

program. You can also use the Stack.h template in this module.

Program Output

For each test case, output one of these lines:

stack

not stack

which will indicate whether or not the series of operations are behaving like a stack $($in LIFO order$).$

Sample Input

Create a text file with the following lines and use it as input into your program.

$4$

i cat

i dog

r dog

r$\}\backslash$mathrm$\{$ cat

$6$

sunshine

i apple

i street

r apple

r street

r$\}\backslash$mathrm$\{$ sunshine

$2$

red

red

i blue

i green

r green

#include

#include

#include

using namespace std;

#define INPUT$\_$FILE "test.txt$"$

int main$()\{$

ifstream f$($INPUT$\_$FILE$)$;

string tmp;

bool failed $=$ false;

if $(!$f$.$good$())\{$

cout $$ "Invalid file." $$ endl;

exit$(-1)$;

$\}$

while $($true$)\{$

getline$($f$,$ tmp$)$;

if $($f$.$eof$())$

return $0$;

failed $=$ false;

int n $=$ atoi$($tmp$.$c$\_$str$())$;

stack st;

while $($n$--)\{$

getline$($f$,$ tmp$)$;

char op $=$ tmp$[0]$;

string word $=$ tmp$.$substr$(2)$;

if $($op $==\text{'}$i$\text{'})\{$

st$.$push$($word$)$;

$\}$ else if $($op $==\text{'}$r$\text{'})\{$

if $($st$.$empty$()||$ st$.$top$()!=$ word$)\{$

failed $=$ true;

$\}$ else $\{$

st$.$pop$()$;

$\}$

$\}$

$\}$

if $(!$st$.$empty$())\{$

failed $=$ true;

$\}$

if $($failed$)\{$

cout $$ "not stack" $$ endl;

$\}$ else $\{$

cout $$ "stack" $$ endl;

$\}$

$\}$

return $0$;

$\}$

the output when I run the code is: Invalid file.

Program ended with exit code: $255$

can you help me fix it because it is not letting me input this: $4$

i cat

i dog

r dog

r cat

$6$

i sunshine

i apple

i street

r apple

r street

r sunshine

$2$

i red

r red

$3$

i blue

i green

r green