@@ -119,21 +119,23 @@ Thanks for [@yihong0618](https://.com/yihong0618) provided a workaround wh
 
 
 ## Settings
-| Setting Name | Description | Default Value |
-| --------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------ |
-| `leetcode.hideSolved` | Specify to hide the solved problems or not | `false` |
-| `leetcode.showLocked` | Specify to show the locked problems or not. Only Premium users could open the locked problems | `false` |
-| `leetcode.defaultLanguage` | Specify the default language used to solve the problem. Supported languages are: `bash`, `c`, `cpp`, `csharp`, `golang`, `java`, `javascript`, `kotlin`, `mysql`, `php`, `python`,`python3`,`ruby`,`rust`, `scala`, `swift`, `typescript` | `N/A` |
-| `leetcode.useWsl` | Specify whether to use WSL or not | `false` |
-| `leetcode.endpoint` | Specify the active endpoint. Supported endpoints are: `leetcode`, `leetcode-cn` | `leetcode` |
-| `leetcode.workspaceFolder` | Specify the path of the workspace folder to store the problem files. | `""` |
-| `leetcode.filePath` | Specify the relative path under the workspace and the file name to save the problem files. More details can be found [here](https://.com/LeetCode-OpenSource/vscode-leetcode/wiki/Customize-the-Relative-Folder-and-the-File-Name-of-the-Problem-File). | |
-| `leetcode.enableStatusBar` | Specify whether the LeetCode status bar will be shown or not. | `true` |
-| `leetcode.editor.shortcuts` | Specify the customized shortcuts in editors. Supported values are: `submit`, `test`, `star`, `solution` and `description`. | `["submit, test"]` |
-| `leetcode.enableSideMode` | Specify whether `preview`, `solution` and `submission` tab should be grouped into the second editor column when solving a problem. | `true` |
-| `leetcode.nodePath` | Specify the `Node.js` executable path. for example, C:\Program Files\nodejs\node.exe | `node` |
-| `leetcode.showCommentDescription` | Specify whether to include the problem description in the comments | `false` |
-| `leetcode.useEndpointTranslation` | Use endpoint's translation (if available) | `true` |
+
+| Setting Name | Description | Default Value |
+| --------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------ |
+| `leetcode.hideSolved` | Specify to hide the solved problems or not | `false` |
+| `leetcode.showLocked` | Specify to show the locked problems or not. Only Premium users could open the locked problems | `false` |
+| `leetcode.defaultLanguage` | Specify the default language used to solve the problem. Supported languages are: `bash`, `c`, `cpp`, `csharp`, `golang`, `java`, `javascript`, `kotlin`, `mysql`, `php`, `python`,`python3`,`ruby`,`rust`, `scala`, `swift`, `typescript` | `N/A` |
+| `leetcode.useWsl` | Specify whether to use WSL or not | `false` |
+| `leetcode.endpoint` | Specify the active endpoint. Supported endpoints are: `leetcode`, `leetcode-cn` | `leetcode` |
+| `leetcode.workspaceFolder` | Specify the path of the workspace folder to store the problem files. | `""` |
+| `leetcode.filePath` | Specify the relative path under the workspace and the file name to save the problem files. More details can be found [here](https://.com/LeetCode-OpenSource/vscode-leetcode/wiki/Customize-the-Relative-Folder-and-the-File-Name-of-the-Problem-File). | |
+| `leetcode.enableStatusBar` | Specify whether the LeetCode status bar will be shown or not. | `true` |
+| `leetcode.editor.shortcuts` | Specify the customized shortcuts in editors. Supported values are: `submit`, `test`, `star`, `solution` and `description`. | `["submit, test"]` |
+| `leetcode.enableSideMode` | Specify whether `preview`, `solution` and `submission` tab should be grouped into the second editor column when solving a problem. | `true` |
+| `leetcode.nodePath` | Specify the `Node.js` executable path. for example, C:\Program Files\nodejs\node.exe | `node` |
+| `leetcode.showCommentDescription` | Specify whether to include the problem description in the comments | `false` |
+| `leetcode.useEndpointTranslation` | Use endpoint's translation (if available) | `true` |
+| `leetcode.colorizeProblems` | Add difficulty badge and colorize problems files in explorer tree | `true` |
 
 ## Want Help?
 

@@ -8,7 +8,7 @@
 "license": "MIT",
 "icon": "resources/LeetCode.png",
 "engines": {
-"vscode": "^1.50.0"
+"vscode": "^1.57.0"
 },
 "repository": {
 "type": "git",
@@ -671,6 +671,12 @@
 "default": "node",
 "scope": "application",
 "description": "The Node.js executable path. for example, C:\\Program Files\\nodejs\\node.exe"
+},
+"leetcode.colorizeProblems": {
+"type": "boolean",
+"default": true,
+"scope": "application",
+"description": "Add difficulty badge and colorize problems files in explorer tree."
 }
 }
 }
@@ -689,7 +695,7 @@
 "@types/mocha": "^2.2.42",
 "@types/node": "^14.14.33",
 "@types/require-from-string": "^1.2.0",
-"@types/vscode": "1.50.0",
+"@types/vscode": "1.57.0",
 "tslint": "^5.20.1",
 "typescript": "^4.3.2"
 },

@@ -1,7 +1,7 @@
 // Copyright (c) jdneo. All rights reserved.
 // Licensed under the MIT license.
 
-import { Command } from "vscode";
+import { Command, Uri } from "vscode";
 import { IProblem, ProblemState } from "../shared";
 
 export class LeetCodeNode {
@@ -55,4 +55,13 @@ export class LeetCodeNode {
 };
 }
 
+public get uri(): Uri {
+return Uri.from({
+scheme: "leetcode",
+authority: this.isProblem ? "problems" : "tree-node",
+path: `/${this.id}`, // path must begin with slash /
+query: `difficulty=${this.difficulty}`,
+});
+}
+
 }

@@ -51,6 +51,7 @@ export class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCod
 collapsibleState: element.isProblem ? vscode.TreeItemCollapsibleState.None : vscode.TreeItemCollapsibleState.Collapsed,
 iconPath: this.parseIconPathFromProblemState(element),
 command: element.isProblem ? element.previewCommand : undefined,
+resourceUri: element.uri,
 contextValue,
 };
 }

@@ -0,0 +1,40 @@
+import { URLSearchParams } from "url";
+import { FileDecoration, FileDecorationProvider, ProviderResult, ThemeColor, Uri, workspace, WorkspaceConfiguration } from "vscode";
+
+export class LeetCodeTreeItemDecorationProvider implements FileDecorationProvider {
+private readonly DIFFICULTY_BADGE_LABEL: { [key: string]: string } = {
+easy: "E",
+medium: "M",
+hard: "H",
+};
+
+private readonly ITEM_COLOR: { [key: string]: ThemeColor } = {
+easy: new ThemeColor("charts.green"),
+medium: new ThemeColor("charts.yellow"),
+hard: new ThemeColor("charts.red"),
+};
+
+public provideFileDecoration(uri: Uri): ProviderResult<FileDecoration> {
+if (!this.isDifficultyBadgeEnabled()) {
+return;
+}
+
+if (uri.scheme !== "leetcode" && uri.authority !== "problems") {
+return;
+}
+
+const params: URLSearchParams = new URLSearchParams(uri.query);
+const difficulty: string = params.get("difficulty")!.toLowerCase();
+return {
+badge: this.DIFFICULTY_BADGE_LABEL[difficulty],
+color: this.ITEM_COLOR[difficulty],
+};
+}
+
+private isDifficultyBadgeEnabled(): boolean {
+const configuration: WorkspaceConfiguration = workspace.getConfiguration();
+return configuration.get<boolean>("leetcode.colorizeProblems", false);
+}
+}
+
+export const leetCodeTreeItemDecorationProvider: LeetCodeTreeItemDecorationProvider = new LeetCodeTreeItemDecorationProvider();

@@ -14,6 +14,7 @@ import * as test from "./commands/test";
 import { explorerNodeManager } from "./explorer/explorerNodeManager";
 import { LeetCodeNode } from "./explorer/LeetCodeNode";
 import { leetCodeTreeDataProvider } from "./explorer/LeetCodeTreeDataProvider";
+import { leetCodeTreeItemDecorationProvider } from "./explorer/LeetCodeTreeItemDecorationProvider";
 import { leetCodeChannel } from "./leetCodeChannel";
 import { leetCodeExecutor } from "./leetCodeExecutor";
 import { leetCodeManager } from "./leetCodeManager";
@@ -47,6 +48,7 @@ export async function activate(context: vscode.ExtensionContext): Promise<void>
 markdownEngine,
 codeLensController,
 explorerNodeManager,
+vscode.window.registerFileDecorationProvider(leetCodeTreeItemDecorationProvider),
 vscode.window.createTreeView("leetCodeExplorer", { treeDataProvider: leetCodeTreeDataProvider, showCollapseAll: true }),
 vscode.commands.registerCommand("leetcode.deleteCache", () => cache.deleteCache()),
 vscode.commands.registerCommand("leetcode.toggleLeetCodeCn", () => plugin.switchEndpoint()),