Merge pull request #99 from Joshua-Lu/patch-15

更新 0501.二叉搜索树中的众数 Java版本

problems/0501.二叉搜索树中的众数.md

@@ -344,46 +344,53 @@ public:
 
 
 Java：
-```java
+
+```Java
 class Solution {
-    private LinkedList<Integer> list = new LinkedList<>();
-    private int currentValue;
-    private int count;
-    private int maxCount;
+    ArrayList<Integer> resList;
+    int maxCount;
+    int count;
+    TreeNode pre;
+
     public int[] findMode(TreeNode root) {
-        count = 0;
+        resList = new ArrayList<>();
         maxCount = 0;
-        currentValue = root.val;
-        findModeTrl(root);
-        int[] res = new int[list.size()];
-        for (int i = 0; i < res.length; i++) {
-            res[i] = list.get(i);
+        count = 0;
+        pre = null;
+        findMode1(root);
+        int[] res = new int[resList.size()];
+        for (int i = 0; i < resList.size(); i++) {
+            res[i] = resList.get(i);
         }
         return res;
     }
 
-    private void findModeTrl (TreeNode root) {
-        if (root == null) return;
-        findModeTrl(root.left);
-        if (root.val == currentValue) {
-            count++;
-        } else {
-            currentValue = root.val;
+    public void findMode1(TreeNode root) {
+        if (root == null) {
+            return;
+        }
+        findMode1(root.left);
+
+        int rootValue = root.val;
+        // 计数
+        if (pre == null || rootValue != pre.val) {
             count = 1;
+        } else {
+            count++;
         }
-
-        if (count == maxCount) {
-            list.add(root.val);
-        } else if (count > maxCount) {
+        // 更新结果以及maxCount
+        if (count > maxCount) {
+            resList.clear();
+            resList.add(rootValue);
             maxCount = count;
-            list.clear();
-            list.add(currentValue);
+        } else if (count == maxCount) {
+            resList.add(rootValue);
         }
+        pre = root;
 
-        findModeTrl(root.right);
+        findMode1(root.right);
     }
 }
-
 ```
 
 Python：