九月刷题给米接龙活动（小伙伴们冲冲冲）

All Paths From Source to Target 简单dfs medium
Valid Palindrome II 简单递归 easy
Interval List Intersections 简单逻辑题 medium

第十四天三题
Student Attendance Record II : dp on ProL and P, insert 'A' to n-1 length string ( PorL[i] * PorL[n-1-i] )
Lowest Common Ancestor of a Binary Tree: dfs, find two paths to two nodes using preorder traversal with stack or dequeue ( or use hashmap to record parents of the nodes, find two nodes and find their common parents using the map, then dfs can be easier to write, normal recursion should work )
Expressive Words: push char, count of S into a vector, process each word and compare with the vector

明天要开始打卡亚麻tag！

计算器三部曲

9/25 刷题打卡
1. Longest substring with at most k distinct characters: 双指针, popitem
2. Transpose Matrix: a[i][j] = a[j][i]
3. Minimum Path Sum: DP

973        K Closest Points to Origin        divide and conquer
139        Word Break        DP
199        Binary Tree Right Side View        Trees

CathYEHB 发表于 2020-9-25 23:02
973        K Closest Points to Origin        divide and conquer
139        Word Break        DP
199        Binary Tree Right Side Vie ...

不好意思我不知道怎么给前面的同学加大米，点了“评分”没有反应。。

打卡第82天 2020.09.25
551. 学生出勤记录 I

今天状态不好，做个简单题激励一下自己。

打卡一道
1. valid palindrome

打卡 medium 题