From 383c9cb1705b6a0760a5208ff879a1cf56c35eb8 Mon Sep 17 00:00:00 2001 From: daniel1n <54945782+daniel1n@users.noreply.github.com> Date: Thu, 1 Jul 2021 18:25:51 +0800 Subject: [PATCH] =?UTF-8?q?Update=200501.=E4=BA=8C=E5=8F=89=E6=90=9C?= =?UTF-8?q?=E7=B4=A2=E6=A0=91=E4=B8=AD=E7=9A=84=E4=BC=97=E6=95=B0.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit java的暴力解法(map记录频率) --- problems/0501.二叉搜索树中的众数.md | 34 ++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/problems/0501.二叉搜索树中的众数.md b/problems/0501.二叉搜索树中的众数.md index d2326d67..66be790f 100644 --- a/problems/0501.二叉搜索树中的众数.md +++ b/problems/0501.二叉搜索树中的众数.md @@ -345,6 +345,40 @@ public: Java: +暴力法 +```java +class Solution { + public int[] findMode(FindModeInBinarySearchTree.TreeNode root) { + Map map = new HashMap<>(); + List list = new ArrayList<>(); + if (root == null) return list.stream().mapToInt(Integer::intValue).toArray(); + // 获得频率 Map + searchBST(root, map); + List> 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 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 resList;