Please can someone tell me what's wrong with my code on spy life

Question

#include <iostream>
using namespace std;
int main() {
string sentence;
string new_sentence;
int i, j = 0, len;
getline(cin, sentence);
len = sentence.length();
char sentences [len];
for(int i = 0; i <= len; i++){
if((sentence[i] >= 'a' && sentence[i] <= 'z') || (sentence[i] >= 'A' && sentence[i] <= 'Z') || sentence[i] == ' '){
sentences[j] = sentence[i];
j++;
}
}
new_sentence = sentences;
for(i = 0, j = new_sentence.length()-1; i < (new_sentence.length()/2); ++i, --j){
int temp;
temp = new_sentence[i];
new_sentence[i] = new_sentence[j];
new_sentence[j] = temp;
}
for(i = 0; i < new_sentence.length()+1; i++){
cout << new_sentence[i];
}
return 0;
}

Answer 1

Well many people have the same proplem and are not able to solve test case 5. Could anyone tell what is test case 5

Answer 2

Thanks for the fast Answer Alexandr!!
But I still don’t find the Mistake of my code. Could you please help a 15 year old guy?!?
#include <iostream>
using namespace std;
int main() {
int length=0;
string b;
getline(cin,b);
while(b[length]!=*(new char)){
length++;
}
char a[length];
int pos=0;
for(int i=0;b[i]!=*(new char);i++)
{
if(b[i]>64&&b[i]<91)
{
a[pos]=b[i];
pos++;
}
if(b[i]>96&&b[i]<123)
{
a[pos]=b[i];
pos++;
}
if(b[i]==32)
{
a[pos]=b[i];
pos++;
}
}
char c[pos];
for(int i=0;i<pos;i++)
c[i]=a[pos-i-1];
cout << c;
return 0;
}
*/