the spy life test ( fails test case 5)

Question

this is my code for the challenge the spy life test .
My code is passing 4 cases out of 5. I don't know what the problem is .
could you help me with this .
the code was written with c++.
https://code.sololearn.com/cJTaK33K8w7F/#cpp

#include <iostream>
#include <string>
using namespace std;
int main () {
string input ;
char temp [30] ;
int j = 0;
getline (cin, input);
for(int i =0 ; input[i];i++){

if((input[i]>='a'&& input[i]<='z')||(input[i]>='A'&&input[i]<='Z')|| (input[i]==' ')){

temp[j++]=input[i];
}
}
char output [j];
for (int i = 0 ; i <=j/2 ; i ++){
output [i] = temp [j-i-1];
output [j-i-1] = temp [i];
}
output [j]=' ';

cout << output ;
return 0 ;
}

Answer 1

Line 21

output[j] = '\0';

...seems to solve your problem...

Answer 2

It seems you forgot to add the null character to your char strings!

Answer 3

Try to learn STL for better understanding of the problem. https://code.sololearn.com/cvv4i17S3MFT/?ref=app