refactor code #112

Author: diguage

docs/0112-path-sum.adoc

@@ -26,3 +26,5 @@ return true, as there exist a root-to-leaf path `5->4->11->2` which sum is 22.
 === 解题分析
 
 减去当前节点值的只，然后递归调用，到叶子节点和目标值相等即可。
+
+注意把代码写简化点！

src/main/java/com/diguage/algorithm/leetcode/_0112_PathSum.java

@@ -25,21 +25,11 @@ public boolean hasPathSum(TreeNode root, int sum) {
         if (Objects.isNull(root)) {
             return false;
         }
-        if (Objects.nonNull(root) && root.val == sum
-                && Objects.isNull(root.left) && Objects.isNull(root.right)) {
-            return true;
+        sum -= root.val;
+        if (  Objects.isNull(root.left) && Objects.isNull(root.right)) {
+            return sum == 0;
         }
-        boolean result = false;
-        if (Objects.nonNull(root.left)) {
-            result = hasPathSum(root.left, sum - root.val);
-        }
-        if (result) {
-            return true;
-        }
-        if (Objects.nonNull(root.right)) {
-            result = hasPathSum(root.right, sum - root.val);
-        }
-        return result;
+        return hasPathSum(root.left, sum) || hasPathSum(root.right, sum);
     }
 
     public static void main(String[] args) {