①leetcode 比特位计数 （根据剑指offer每次减1然后与运算。本题更优的解：当知道了i的比特数，就知道了2 * i和 2* i+1的比特数） https://leetcode-cn.com/problems/counting-bits/submissions/ 前k个高频元素 https://leetcode-cn.com/problems/top-k-frequent-elements/solution/leetcode-di-347-hao-wen-ti-qian-k-ge-gao-pin-yuan-/ 字符串解码： https://leetcode-cn.com/problem...

①leetcode 301-337 删除无效的括号（放弃） https://leetcode-cn.com/problems/remove-invalid-parentheses/solution/shan-chu-wu-xiao-de-gua-hao-by-leetcode-9w8au/ 含有冷冻期的股票问题 https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/submissions/ 戳气球 https://leetcode-cn.com/problems/burst-balloons...

①leetcode 完全平方数：（四平方和，非线性dp） https://leetcode-cn.com/problems/perfect-squares/ 移动零 https://leetcode-cn.com/problems/move-zeroes/submissions/ 寻找重复数（1-n） https://leetcode-cn.com/problems/find-the-duplicate-number/submissions/ 最长上升子序列 https://leetcode-cn.com/problems/longest-increasing-subsequence/solu...

①leetcode 234-240 回文链表 https://leetcode-cn.com/problems/palindrome-linked-list/submissions/ 二叉树公共节点 https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-tree/submissions/ 搜索矩阵 https://leetcode-cn.com/problems/search-a-2d-matrix-ii/solution/sou-suo-er-wei-ju-zhen-by-19216801-l53y/ 滑动窗口...

①leetcode 207-226 反转二叉树 https://leetcode-cn.com/problems/invert-binary-tree/solution/ 查找第k个最大元素 https://leetcode-cn.com/problems/kth-largest-element-in-an-array/submissions/ 实现前缀树(在公共空间声明，在构造函数初始化) https://leetcode-cn.com/problems/implement-trie-prefix-tree/solution/qian-zhui-shu-by-19216801-h9e2/ D...

①leetcode 160-206 相交链表的第一个节点 https://leetcode-cn.com/problems/intersection-of-two-linked-lists/submissions/ 数组中超过一半的元素 https://leetcode-cn.com/problems/majority-element/solution/ 打家劫舍（dp） https://leetcode-cn.com/problems/house-robber/ 岛屿数量 https://leetcode-cn.com/problems/number-of-islands/solution/...

①leetcode 至今，按顺序刷到了140题，剩下的10天刷完top100，把时间转移到项目和八股文上。 快慢指针找链表环 https://leetcode-cn.com/problems/linked-list-cycle/submissions/ 找入环节点证明 https://leetcode-cn.com/problems/linked-list-cycle-ii/solution/huan-xing-lian-biao-ii-by-leetcode-solution/ 链表排序 O（n²）解法可以使用插入 本题要求O（NlogN）的解法，快排，归并，和堆是O（NlogN）的，使用快...

①leetcode 复习111-120 数组中出现一次的数字（异或） https://leetcode-cn.com/problems/single-number/submissions/ 找数组中出现三次的数字（32位分别%3，或数电） https://leetcode-cn.com/problems/single-number-ii/submissions/ 复制带random的链表 https://leetcode-cn.com/problems/copy-list-with-random-pointer/submissions/ 单词拆分判断：（dp） https://leetcode...

①leetcode 复习：101-110 回溯+dp 回文子串 https://leetcode-cn.com/problems/palindrome-partitioning/solution/hui-su-dpyou-hua-by-19216801-j46l/ 回文串2（两个dp） https://leetcode-cn.com/problems/palindrome-partitioning-ii/submissions/ 复制图 https://leetcode-cn.com/problems/clone-graph/submissions/ 负数油表 最近发现只要是字符串相关的问题就...

①leetcode 复习91-100 单词接龙2 https://leetcode-cn.com/problems/word-ladder-ii/solution/dan-ci-jie-long-2-by-19216801-rhtn/ 单词接龙 https://leetcode-cn.com/problems/word-ladder/ 最长序列 https://leetcode-cn.com/problems/longest-consecutive-sequence/solution/zui-chang-xu-lie-by-19216801-4wzi/ 根节点到叶节点的数字和 https://...

①leetcode 复习：81-90 股票最大值1 https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock/solution/gu-piao-1-by-19216801-eoq9/ 股票最大值2 https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-ii/solution/mai-mai-gu-piao-2-by-19216801-wp59/ 股票最大值3 https://leetcode-cn.com/problems/best-time-to...

①leetcode 复习71-80 链接完全二叉树二叉树每层节点（递归或层次遍历） https://leetcode-cn.com/problems/populating-next-right-pointers-in-each-node/submissions/ 链接二叉树的每层节点（使用上一层的链表结构，层次遍历） https://leetcode-cn.com/problems/populating-next-right-pointers-in-each-node-ii/solution/lian-jie-er-cha-shu-mei-ceng-jie-dian-by-0fnk/ 杨辉三角...

①leetcode 复习：61-70 二叉树最小深度： https://leetcode-cn.com/problems/minimum-depth-of-binary-tree/ 二叉树路径和 https://leetcode-cn.com/problems/path-sum/solution/ 回溯法找所有路径 https://leetcode-cn.com/problems/path-sum-ii/submissions/ 二叉树展开成链表 https://leetcode-cn.com/problems/flatten-binary-tree-to-linked-list/submis...

①leetcode 复习第51-60题 中序及后序构造二叉树 https://leetcode-cn.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal/solution/zhong-xu-hou-xu-gou-zao-er-cha-shu-by-19-ka1t/ 层次遍历2 https://leetcode-cn.com/problems/binary-tree-level-order-traversal-ii/solution/ceng-ci-bian-li-bian-xing-by-1921680...