corner case for 4-pallindrome-permutations.cpp might be wrong

[srliuLouis]

I just referred to this practice and found that the result might be wrong if the string pattern is "TTE"

[sergio-nsk]

Please elaborate what is not correct. The result is correct: https://ideone.com/HXBjlH
The output is valid, TTE is a permutation of the palindrome TET:

Does "TTE"  has a string whose permutation is a pallindrome? ( 1 for true, 0 for false ) :
Approach 1:1
Approach 2:1
Approach 3:1