diff --git "a/394.\345\255\227\347\254\246\344\270\262\350\247\243\347\240\201.js" "b/394.\345\255\227\347\254\246\344\270\262\350\247\243\347\240\201.js"
new file mode 100644
index 0000000..1d50507
--- /dev/null
+++ "b/394.\345\255\227\347\254\246\344\270\262\350\247\243\347\240\201.js"
@@ -0,0 +1,42 @@
+/**
+ * @param {string} s
+ * @return {string}
+ */
+function decodeString(s) {
+  let strStack = []
+  let numStack = []
+  let res = ''
+  let num = 0
+  for (let c of s) {
+    if (/\d/.test(c)) {
+      num = num * 10 + +c // 算出倍数
+    } else if (c === '[') {
+      numStack.push(num) // 倍数num进入栈等待
+      strStack.push(res) // result串入栈
+      res = ''
+      num = 0
+    } else if (c === ']') {
+      let repeatTimes = numStack.pop() // 获取拷贝次数
+      res = strStack.pop() + res.repeat(repeatTimes)
+    } else {
+      res += c
+    }
+  }
+  console.log(res)
+  return res
+}
+// 测试用例
+decodeString('3[a2[c]]')
+
+/** 示例 1：
+  输入：s = "3[a]2[bc]"
+  输出："aaabcbc"
+
+  示例 2：
+  输入：s = "3[a2[c]]"
+  输出："accaccacc"
+
+  示例 3：
+  输入：s = "2[abc]3[cd]ef"
+  输出："abcabccdcdcdef" 
+*/