Why getting all test failed despite my output the same as expected output.

Question

#include <iostream>
#include <string>
using namespace std;

int main() {
string word;

getline(cin, word);

for (int i = word.length(); i >= 0; i--) {
cout << word[i];
}

return 0;
}

Answer 1

// To big index. It should be:

for (int i = word.length()-1; i >= 0; i--) {
cout << word[i];
}

return 0;
}

Answer 2

Thanks so much guys i got it now right

Answer 3

But is showing all test fail i'm confused