Create LongestPalindrome.java

Author: sudoshivesh

easy/LongestPalindrome.java

@@ -0,0 +1,17 @@
+//409. Longest Palindrome
+class Solution {
+  public int longestPalindrome(String s) {
+    int ans = 0;
+    int[] count = new int[128];
+
+    for (final char c : s.toCharArray())
+      ++count[c];
+
+    for (final int c : count)
+      ans += c % 2 == 0 ? c : c - 1;
+
+    final boolean hasOddCount = Arrays.stream(count).anyMatch(c -> c % 2 == 1);
+
+    return ans + (hasOddCount ? 1 : 0);
+  }
+}