From 120bca22a0d8e28e5e00061df738a6db7f2c339c Mon Sep 17 00:00:00 2001
From: Ultraman <1394466835@qq.com>
Date: Sat, 18 May 2024 13:41:19 +0800
Subject: [PATCH] feat: update

---
 README.md |  1 +
 kata.md   | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)
 create mode 100644 kata.md

diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -2,6 +2,7 @@ The best thing to do is have fun.
 
 - [列表 - 韩立的修炼](/)
 - [Hobby Projects](/hobby_projects.md)
+- [Kata](/kata.md)
 - **2024-05**
   - [如何搭建新个网段，并配有一台机器挂载](/2024/05/new_nic_with_hub_switch.md)
   - [RC-incubator-answer 论坛](/2024/05/incubator-answer.md)
diff --git a/kata.md b/kata.md
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+# What can i say
+
+## [114. Flatten Binary Tree to Linked List](https://leetcode.cn/problems/flatten-binary-tree-to-linked-list/)
+
+如果使用 O(n) space 比较简单，前序遍历回放即可。
+
+O(1) space 的话，利用递归思想 flatten(left), flatten(right)，最后再将 right, left 合并。
+
+## [199. Binary Tree Right Side View](https://leetcode.cn/problems/binary-tree-right-side-view/)
+
+层序遍历，每层取最后一个元素
+
+## [2462. Total Cost to Hire K Workers](https://leetcode.cn/problems/total-cost-to-hire-k-workers/)
+
+使用两个堆一个维护前面的，一个维护后面的最小 cost  
+需要注意两个堆中元素不能重复即(2\*candidates+k<=n)，如果元素不足，而可以直接排序取。
+
+## [1329. Sort the Matrix Diagonally](https://leetcode.cn/problems/sort-the-matrix-diagonally/)
+
+对角线特性，同一对角线的元素 i-j 都相等，可以先收集，排序，放回。
+
+[数学解法](https://leetcode.cn/problems/sort-the-matrix-diagonally/solutions/2760094/dui-jiao-xian-pai-xu-fu-yuan-di-pai-xu-p-uts8/)
+
+## [1. Two Sum](https://leetcode.cn/problems/two-sum/)
+
+字典运用
+
+## [1017. Convert to Base -2](https://leetcode.cn/problems/convert-to-base-2/)
+
+十进制 转 X 进制
+
+```
+ n = a * (x)^5 + b * (x)^4 + c * (x)^3 + d * (x)^2 + e * (x)^1 + f * (x)^0
+```
+
+本质就是求 abcdef，可以每次求出 f(n%x)，然后 n-f，n//=x 就是下一个
+
+## [2007. Find Original Array From Doubled Array](https://leetcode.cn/problems/find-original-array-from-doubled-array/)
+
+首先排序，每次配对最小的元素
+
+## [Training on Decode the Morse code | Codewars](https://www.codewars.com/kata/54b724efac3d5402db00065e/train/go)