Test for palindromic permutations
CanStringBePalindromeHash.javapublic static boolean canStringBeAPalindrome(String s) {
Map<Character, Integer> hash = new HashMap<>();
// Insert each char into hash.
for (char c : s.toCharArray()) {
if (!hash.containsKey(c)) {
hash.put(c, 1);
} else {
hash.put(c, hash.get(c) + 1);
}
}
// A string can be permuted as a palindrome if the number of odd time
// chars <= 1.
int oddCount = 0;
for (Map.Entry<Character, Integer> p : hash.entrySet()) {
if ((p.getValue() & 1) != 0 && ++oddCount > 1) {
break;
}
}
return oddCount <= 1;
}
}
CanStringBePalindromeSorting.java
