A PhD Student Cornered by LeetCode
博士生被Leetcode逼到死角
Champaign, 2026
Translation by Claude.
I can’t stand still and I can’t sit still. I refuse to waste the daylight hours, and then by nightfall I’m nodding off. I look up at the lake outside my window: the ducks are huddled under the trees, a Black guy is out on his run, shirtless. Everything as it always is.
How can there be so many binary trees waiting to be traversed? They’re like the endless letters I wrote in middle school on behalf of Li Hua, the made-up student of every Chinese English exam, to an American pen pal neither of us had ever met. How have you been lately? It’s snowing hard in my hometown, and Lunar New Year is just around the corner. When the red lanterns are lit, remember to come and see me.
Every fall, when internship season comes around, I subscribe to LeetCode Premium and make a resolution: even if I bomb a dynamic programming question in this year’s interviews, as long as I keep practicing every night, I’ll sweep through every problem by next fall.
Much later, I open my credit card account and find, to my surprise, 39 dollars charged every month. I blame myself for having too many subscriptions and losing track of them, and, full of regret, I firmly cancel.
Grind, grind, grind. My narrowed life falls back into the repetitive rhythm of years ago. I switch into low-power mode, stop thinking, and focus only on getting problem after problem right.
Now and then I do stop to think: does what I’m doing mean anything? I just toss Claude a function name and its parameters, and it pours out the LeetCode problem number, the algorithm and the complexity all at once, leaving me to stare at that big O of n log n and chew on it for a long time.
站也不是，坐也不是，白天的时间不愿浪费，等到夜晚又昏昏欲睡。抬头看看窗外的湖，鸭子们蹲在树下，黑人大哥赤裸着跑步，一切如故。
怎么有那么多二叉树等待遍历，好像中学时帮李华写给素未谋面的美国笔友的、数不尽的信件。你最近好吗？我的家乡下起大雪，农历新年就在转角处，红灯初上时，记得来看我。
每年秋季找实习，都要订阅一份Leetcode premium，下定决心，即使今年面试时挂掉一道动态规划，只要每晚坚持练习，也必将在下个秋季横扫题目。
过了许久打开信用卡账户，惊奇地发现每月被划走39元，责怪自己订阅太多，管理失效，在懊悔中坚定取消。
刷呀刷，狭窄的生活又落回多年前的重复节奏，我开启低电量模式，不再思考，只顾把一道道题目写对写好。
偶尔也思考，我做得事情有意义吗？只甩给claude函数名和参数，它就一股脑儿把leetcode题号、算法、复杂度吐出来，再由我盯着线性乘对数的大写的O咀嚼很久。