sum of left leaves

Author: fishercoder1534

Contest/src/_20160924_6th_contest/SumofLeftLeaves.java renamed to EASY/src/easy/SumofLeftLeaves.java

@@ -1,4 +1,4 @@
-package _20160924_6th_contest;
+package easy;
 
 import classes.TreeNode;
 
@@ -26,4 +26,21 @@ private int dfs(TreeNode root, int result, boolean left) {
         }
         return leftResult + rightResult;
     }
+    
+    private class Solution_more_concise{
+
+        public int sumOfLeftLeaves(TreeNode root) {
+            int sum = 0;
+            if(root == null) return sum;
+            if(root.left != null){
+                if(root.left.left == null && root.left.right == null) sum += root.left.val;
+                else sum += sumOfLeftLeaves(root.left);
+            }
+            if(root.right != null){
+                sum += sumOfLeftLeaves(root.right);
+            }
+            return sum;
+        }
+
+    }
 }

README.md

@@ -5,6 +5,7 @@
 |419|[Battleships in a Board](https://leetcode.com/problems/battleships-in-a-board/)|[Solution](../../blob/master/MEDIUM/src/medium/BattleshipsinaBoard.java) | O(n^2) |O(1) | Medium| DFS
 |415|[Add Strings](https://leetcode.com/problems/add-strings/)|[Solution](../../blob/master/EASY/src/easy/AddStrings.java)| O(n)|O(1) | Easy|
 |412|[Fizz Buzz](https://leetcode.com/problems/fizz-buzz/)|[Solution](../../blob/master/EASY/src/easy/FizzBuzz.java)| O(n)|O(1) | Easy|
+|404|[Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves/)|[Solution](../../blob/master/EASY/src/easy/SumofLeftLeaves.java)| O(n)|O(h) | Easy|
 |398|[Random Pick Index](https://leetcode.com/problems/random-pick-index/)|[Solution](../../blob/master/MEDIUM/src/medium/RandomPickIndex.java) | | | Medium| Reservoir Sampling
 |397|[Integer Replacement](https://leetcode.com/problems/integer-replacement/)|[Solution](../../blob/master/EASY/src/easy/IntegerReplacement.java)| ? | ? | Easy| BFS
 |396|[Rotate Function](https://leetcode.com/problems/rotate-function/)|[Solution](../../blob/master/EASY/src/easy/RotateFunction.java)| O(n^2) could be optimized to O(n) | O(1) | Easy|