Read a $3-$character string from input into variable inString. Declare a Boolean variable isValid and assign isValid with true if inString only contains digits. Otherwise, assign isValid with false.

Ex: If the input is $321,$ then isValid is assigned with true, so the output is:

String is valid

Ex: If the input is $=90,$ then isValid is assigned with false, so the output is:

String is not valid

Note: Use getline$($cin$,$ inString$)$ to read the entire line from input into inString. #include

#include

#include

using namespace std;

int main$()\{$

string inString;

$/*$ Your code goes here $*/$

if $($isValid$)\{$

cout $<<$ "String is valid" $<<$ endl;

$\}$

else $\{$

cout $<<$ "String is not valid" $<<$ endl;

$\}$

return $0$;

$\}$