fix online code-exercise issue, and optimize readme

Sunrisepeak · Sunrisepeak · commit 3138e1d2c0ef · 2026-03-16T07:12:13.000+08:00
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
@@ -13,5 +13,5 @@
   },
   "remoteUser": "vscode",
   "postCreateCommand": "/bin/bash .devcontainer/postCreate.sh",
-  "postAttachCommand": "xlings checker"
+  "postAttachCommand": "d2x checker"
 }
diff --git a/.devcontainer/postCreate.sh b/.devcontainer/postCreate.sh
@@ -9,4 +9,10 @@ if ! command -v xlings >/dev/null 2>&1; then
   curl -fsSL https://d2learn.org/xlings-install.sh | bash
 fi
 
-echo "xlings installed"
+echo "xlings installed"
+
+echo "Installing dependencies (d2x) by xlings..."
+
+xlings install --verbose
+
+echo "Dependencies installed"
diff --git a/README.md b/README.md
@@ -67,6 +67,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker
diff --git a/README.zh.hant.md b/README.zh.hant.md
@@ -67,6 +67,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker
diff --git a/README.zh.md b/README.zh.md
@@ -67,6 +67,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker
diff --git a/book/en/src/README.md b/book/en/src/README.md
@@ -63,6 +63,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker
diff --git a/book/src/README.md b/book/src/README.md
@@ -63,6 +63,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker

Original file line number	Diff line number	Diff line change
`@@ -13,5 +13,5 @@`
`13`	`13`	`},`
`14`	`14`	`"remoteUser": "vscode",`
`15`	`15`	`"postCreateCommand": "/bin/bash .devcontainer/postCreate.sh",`
`16`		`- "postAttachCommand": "xlings checker"`
	`16`	`+ "postAttachCommand": "d2x checker"`
`17`	`17`	`}`