最近抽空做了一場 Cisco 的 OA，說實話，這場測試完全可以算是“福利局”。 整套題一共三道，難度都不高，題型也相對常規，沒有太多刁鑽的點。 答題過程中整體體驗很絲滑，不會有卡頓或者糾結太久的情況。 相比其他大廠動輒燒腦的 OA，Cisco 這場真的算是少見的“白嫖局”。 如果你平時有刷過一些 LeetCode 的經典題型，基本上閉著眼都能順利過關。
Cisco Online Assessment 流程
Cisco 的 OA 形式非常傳統，沒有花哨的附加環節：
題目數量：共 3 道演算法題
時間：總時長 90 分鐘（足夠充裕）
程式設計語言：常見語言都支援（我用的是 C++，體驗流暢）
环境：在線 IDE，比起一些卡頓嚴重的平臺算是很順滑
整體氛圍偏友好，不像某些公司 OA 一上來就時間緊張 + 大數據 case，Cisco 的節奏算是很“體貼”。
Cisco oa questions （真題回顧）
Problem 1: Binary Linked List to Decimal
Problem Statement
A binary number is represented as a singly linked list, where each node contains either 0 or 1.
Given the head of the linked list, convert the binary number into its decimal representation.
Example
binary -> 0 -> 0 -> 1 -> 0 -> 0 -> 1 -> 1 -> null
This corresponds to 010011₂ = 19₁₀.
Input
- The first line: an integer
list_size, the number of nodes in the list. - The second line:
list_sizespace-separated integers (0 or 1), representing the data in each node.
Output
- Print the decimal equivalent of the binary number.
Solution Explanation
- Traverse the linked list while treating it as a binary number.
- Start with
decimal = 0. - For each node, shift
decimalleft by one (multiply by 2) and add the node’s value.
This simulates binary conversion efficiently in O(N) time and O(1) extra space.
Problem 2: Expand String with Patterns
Problem Statement
You are given a string S. The string may contain substrings grouped inside parentheses () which form patterns.
Each pattern is followed by an integer inside curly braces {} which indicates the repeat count.
Rules
- A pattern
(Pi){Ni}should be expanded as the substringPirepeatedNitimes. - For this version, consider simple (non-nested) patterns.
Input
- A single string
inputStr.
Output
- Print the expanded string.
Example
Input:
(ab){3}
Output:
ababab
Solution Explanation
- Scan the string and detect any pattern enclosed in
(). - Read the substring inside parentheses.
- Extract the integer inside
{}. - Repeat the substring accordingly.
This works straightforwardly with O(L × K) time (where L is input length and K is repeat count).
Problem 3: Expand String with Nested Patterns
Problem Statement
This is an advanced version of Problem 2, where patterns can be nested.
Example
(ef((ab){2}cd){2}){2}
Rules
- Each pattern
(Pi){Ni}expands toPirepeatedNitimes. - If patterns are nested, expand the inner ones first.
Input
- A single string
inputStr.
Output
- Print the fully expanded string.
Solution Explanation
- Use a stack-based parsing approach:
- Traverse the string character by character.
- Push characters to a stack until you hit a
). - When
)is found, pop until matching(to extract the pattern. - Immediately after, read the repeat count inside
{}. - Expand the substring and push the result back onto the stack.
- Continue until the full string is processed.
- Join stack contents for the final answer.
This ensures even nested patterns expand correctly.
和其他大廠對比
和 Amazon OA 比：Amazon 有 simulation + debugging + 數學邏輯，心理壓力大。 Cisco 全是常規題，輕鬆很多。
和 Google/Meta OA 比：Google/Meta 偏 hard/medium，Cisco 就是 easy-medium，完全不是一個維度。
和金融類 OA 比：像 SIG、Jane Street 這種，邏輯博弈爆算力。 Cisco 完全不走這條路。
Cisco OA 算是大廠里最溫柔的一批。
小結 & 助攻小貼士
Cisco OA 整體真的算是“友好局”，刷過基礎題的同學基本都能穩穩通過。 但話說回來，大廠校招流程長，後面面試環節往往才是真正的考驗。
如果你担心：OA 时候可能粗心挂分，面试遇到高压问答脑子一片空白，需要临场思路提示或者语音助攻，我们 Programhelp 团队 都能帮你搞定：OA无痕联机代写、VO助攻、甚至全程代面服务……不管是 Cisco 这种“福利 OA”，还是 Amazon/Google 等高压面试，我们都有成熟的方案，帮你从 OA 到 VO 一路稳稳拿下机会。
面試別一個人硬撐，有備胎方案在，心態會輕鬆很多。
