https://leetcode.cn/problems/find-mode-in-binary-search-tree/

Author: masx200

README.md

@@ -10,6 +10,8 @@ leetcode 测试
 
 ##### 包含的内容如下
 
+https://leetcode.cn/problems/find-mode-in-binary-search-tree/
+
 https://leetcode.cn/problems/split-a-string-in-balanced-strings/
 
 https://leetcode.cn/problems/maximum-xor-after-operations/

find-mode-in-binary-search-tree/index.ts

@@ -0,0 +1,10 @@
+import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
+import { default as groupBy } from "https://cdn.skypack.dev/[email protected]/groupBy?dts";
+import inorderTraversal from "../binary-tree-inorder-traversal/index.ts";
+export default function findMode(root: TreeNode | null): number[] {
+    const cnt = groupBy(inorderTraversal(root));
+    const max = Math.max(...Object.values(cnt).map((v) => v.length));
+    return Object.keys(cnt)
+        .filter((k) => cnt[k].length === max)
+        .map(Number);
+}

find-mode-in-binary-search-tree/test.ts

@@ -0,0 +1,11 @@
+import { assertEquals } from "https://deno.land/[email protected]/testing/asserts.ts";
+import { TreeNodeLeetCodeFromJSON } from "../utils/TreeNodeLeetCodeParse.ts";
+import findMode from "./index.ts";
+Deno.test("find-mode-in-binary-search-tree", () => {
+    assertEquals(
+        [[1, null, 2, 2], [0], [300, 23, 2222, 22, 111, 303]]
+            .map((a) => findMode(TreeNodeLeetCodeFromJSON(a)))
+            .map((a) => new Set(a)),
+        [[2], [0], [303, 2222, 111, 22, 23, 300]].map((a) => new Set(a)),
+    );
+});

maximum-xor-after-operations/index.ts

@@ -1,3 +1,3 @@
-export default function maximumXOR(nums: number[]): number {
-    return nums.reduce((pre, cur) => pre | cur, 0);
-}
+export default function maximumXOR(nums: number[]): number {
+    return nums.reduce((pre, cur) => pre | cur, 0);
+}

split-a-string-in-balanced-strings/index.ts

@@ -1,16 +1,16 @@
-export default function balancedStringSplit(s: string): number {
-    let ans = 0,
-        d = 0;
-    for (let i = 0; i < s.length; ++i) {
-        const ch = s[i];
-        if (ch === "L") {
-            ++d;
-        } else {
-            --d;
-        }
-        if (d === 0) {
-            ++ans;
-        }
-    }
-    return ans;
-}
+export default function balancedStringSplit(s: string): number {
+    let ans = 0,
+        d = 0;
+    for (let i = 0; i < s.length; ++i) {
+        const ch = s[i];
+        if (ch === "L") {
+            ++d;
+        } else {
+            --d;
+        }
+        if (d === 0) {
+            ++ans;
+        }
+    }
+    return ans;
+}