xinyu04

摘要： You are given an m x n integer array grid. There is a robot initially located at the top-left corner (i.e., grid[0][0]). The robot tries to move to th 阅读全文

摘要： Given a string s, return the longest palindromic substring in s. Solution 设 \(dp[i][j]\) 表示字串 \(s[i,...,j]\) 是否为回文串。初始化时，每个单独的字符本身就是回文串；长度为2的串只要首尾相同，也 阅读全文

摘要： You are given an integer array coins representing coins of different denominations and an integer amount representing a total amount of money. Return 阅读全文