packageeasy;

importjava.util.HashMap;

importjava.util.Map;

publicclassPalindromePermutation {

publicbooleancanPermutePalindrome(Strings) {

char[]chars =s.toCharArray();

Map<Character,Integer>map =newHashMap<Character,Integer>();

for(charc :chars){

if(!map.containsKey(c))map.put(c,1);

elsemap.put(c,map.get(c)+1);

}

intevenCount =0;

for(Map.Entry<Character,Integer>e :map.entrySet()){

if(e.getValue() %2 !=0)evenCount++;

if(evenCount >1)returnfalse;

}

returntrue;

}

}

|276|[Paint Fence](https://leetcode.com/problems/paint-fence/)|[Solution](../../blob/master/EASY/src/easy/PaintFence.java)| O(n)|O(1) | Easy| DP

|273|[Integer to English Words](https://leetcode.com/problems/integer-to-english-words/)|[Solution]|

|270|[Closest Binary Search Tree Value](https://leetcode.com/problems/closest-binary-search-tree-value/)|[Solution](../../blob/master/EASY/src/easy/ClosestBinarySearchTreeValue.java)| O(h)|O(1) | Easy| DFS

|266|[Palindrome Permutation](https://leetcode.com/problems/palindrome-permutation/)|[Solution](../../blob/master/EASY/src/easy/PalindromePermutation.java)| O(n)|O(1) | Easy| HashMap

|261|[Graph Valid Tree](https://leetcode.com/problems/graph-valid-tree/)|[Solution](../../blob/master/MEDIUM/src/medium/GraphValidTree.java)| O(V+E)|O(V+E)| Medium|

|259|[3Sum Smaller](https://leetcode.com/problems/3sum-smaller/)|[Solution](../../blob/master/MEDIUM/src/medium/_3Sum_Smaller.java)| O(n^2)|O(1)| Medium|

|257|[Binary Tree Paths](https://leetcode.com/problems/binary-tree-paths/)|[Solution](../../blob/master/EASY/src/easy/BinaryTreePaths.java) | O(n*h) | O(h) | DFS/Recursion