Update 0501.二叉搜索树中的众数.md

java的暴力解法(map记录频率)
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daniel1n
2021-07-01 18:25:51 +08:00
committed by GitHub
parent 0f38eb9065
commit 383c9cb170

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@ -345,6 +345,40 @@ public:
Java
暴力法
```java
class Solution {
public int[] findMode(FindModeInBinarySearchTree.TreeNode root) {
Map<Integer, Integer> map = new HashMap<>();
List<Integer> list = new ArrayList<>();
if (root == null) return list.stream().mapToInt(Integer::intValue).toArray();
// 获得频率 Map
searchBST(root, map);
List<Map.Entry<Integer, Integer>> mapList = map.entrySet().stream()
.sorted((c1, c2) -> c2.getValue().compareTo(c1.getValue()))
.collect(Collectors.toList());
list.add(mapList.get(0).getKey());
// 把频率最高的加入 list
for (int i = 1; i < mapList.size(); i++) {
if (mapList.get(i).getValue() == mapList.get(i - 1).getValue()) {
list.add(mapList.get(i).getKey());
} else {
break;
}
}
return list.stream().mapToInt(Integer::intValue).toArray();
}
void searchBST(FindModeInBinarySearchTree.TreeNode curr, Map<Integer, Integer> map) {
if (curr == null) return;
map.put(curr.val, map.getOrDefault(curr.val, 0) + 1);
searchBST(curr.left, map);
searchBST(curr.right, map);
}
}
```
```Java
class Solution {
ArrayList<Integer> resList;