2025-12-19

1390. Four Divisors 题目 1390. Four Divisorshttps://leetcode.com/problems/fourdivisors/ !image97412e94.png 思路分析 !image3922

1980. Find Unique Binary String 题目 1980. Find Unique Binary Stringhttps://leetcode.com/problems/finduniquebinarystring/

2545. Sort the Students by Their Kth Score 题目 2545. Sort the Students by Their Kth Scorehttps://leetcode.com/problems/so

657. Robot Return to Origin 题目 657. Robot Return to Originhttps://leetcode.com/problems/robotreturntoorigin/ !imaged1ba5

StringBuilder API 增 Append & Insert 这是最常用的功能，支持链式调用（Method Chaining）。 StringBuilder sb = new StringBuilder; // 1. append