常用算法记录（二）

常用的面试算法题记录

• 二分法
• 数组
• https://leetcode.cn/problems/move-zeroes/
• 快排
• 75. 颜色分类 https://leetcode.cn/problems/sort-colors/
• 三路快排
• 88题 归并排序的归并
• 215题 经典问题 找第K大元素 
• 排序Onlogn
• 快排On就可以。二分法的原理
• 对撞指针
• 167题 https://leetcode.cn/problems/two-sum-ii-input-array-is-sorted/
• 11题 https://leetcode.cn/problems/container-with-most-water/description/
• 滑动窗口（也是两个指针）
• 209题 https://leetcode.cn/problems/minimum-size-subarray-sum/
• 3题 https://leetcode.cn/problems/longest-substring-without-repeating-characters/
• 438题 https://leetcode.cn/problems/find-all-anagrams-in-a-string/description/
• 76题 https://leetcode.cn/problems/minimum-window-substring/description/
• 567 https://leetcode.cn/problems/permutation-in-string/description/
• 查找表
• set 基本用法 349 https://leetcode.cn/problems/intersection-of-two-arrays/description/
• Map 基本用法 350 https://leetcode.cn/problems/intersection-of-two-arrays-ii/description/
• 1题 https://leetcode.cn/problems/two-sum/description/
• 15题3数之和 https://leetcode.cn/problems/3sum/
• 18题 4数之和 https://leetcode.cn/problems/4sum/description/
• 16题 https://leetcode.cn/problems/3sum-closest/description/
• 链表
• 206 https://leetcode.cn/problems/reverse-linked-list/
• 92题 https://leetcode.cn/problems/reverse-linked-list-ii/description/
• 83题
• 86题
• 328题 https://leetcode.cn/problems/odd-even-linked-list/description/
• 2题
• 445题 https://leetcode.cn/problems/add-two-numbers-ii/description/
• 链表虚拟头结点
• 203题 https://leetcode.cn/problems/remove-linked-list-elements/
• 82题 https://leetcode.cn/problems/remove-duplicates-from-sorted-list-ii/description/
• 21题 https://leetcode.cn/problems/merge-two-sorted-lists/description/
• 复杂的穿针引线 5.4节
• 24题 https://leetcode.cn/problems/swap-nodes-in-pairs/description/
• 25题 https://leetcode.cn/problems/reverse-nodes-in-k-group/
• 147题 https://leetcode.cn/problems/insertion-sort-list/description/
• 148题 https://leetcode.cn/problems/sort-list/
• 不仅仅是穿针引线
• 237题 https://leetcode.cn/problems/delete-node-in-a-linked-list/
• 链表&双指针
• 19题 https://leetcode.cn/problems/remove-nth-node-from-end-of-list/
• 61题 https://leetcode.cn/problems/rotate-list/description/
• 143题 https://leetcode.cn/problems/reorder-list/
• 234题 https://leetcode.cn/problems/palindrome-linked-list/
• 递归和回溯法（回溯是暴力解法，可以通过剪枝降低复杂度）
• 17题 https://leetcode.cn/problems/letter-combinations-of-a-phone-number/submissions/
• 93题 https://leetcode.cn/problems/restore-ip-addresses/
• 131题  https://leetcode.cn/problems/palindrome-partitioning/description/
• 排列问题
• 46题 https://leetcode.cn/problems/permutations/ 借助数学推理 可以有更高效的方法
• 47题 https://leetcode.cn/problems/permutations-ii/
• 组合问题
• 77题 https://leetcode.cn/problems/combinations/description/
• 39题 https://leetcode.cn/problems/combination-sum/description/
• 40题 https://leetcode.cn/problems/combination-sum-ii
• 216题 https://leetcode.cn/problems/combination-sum-iii/description/
• 78题 https://leetcode.cn/problems/subsets/description/
• 90题 https://leetcode.cn/problems/subsets-ii/description/
• 二维平面上的回溯法
• https://leetcode.cn/problems/design-add-and-search-words-data-structure/description/
• 动态规划
• 记忆化搜索 自顶向下的
• 斐波那契数列 fib（n-1 ）+ fib（n-2）; 这种写法性能低。指数级的复杂度。
• 用一个int[n]记录结果。O(n)复杂度。性能问题。还需要考虑越界，取模。
• 用hash也行，没有数组方便。
• 动态规划 自底向上解决问题
• 70题 https://leetcode.cn/problems/climbing-stairs/description/
• 120题 https://leetcode.cn/problems/triangle/description/
• 64题 https://leetcode.cn/problems/minimum-path-sum/description/
• 343题 https://leetcode.cn/problems/integer-break/description/
• 自顶向下 记忆搜索 arr[i]  递归
• 自底向上 动态规划 arr[n]  双重循环 求arr[n]
• 279 https://leetcode.cn/problems/perfect-squares/description/
• 也是背包问题：完全背包  https://mp.weixin.qq.com/s/xmgK7SrTnFIM3Owpk-emmg
• 91题 https://leetcode.cn/problems/decode-ways/description/
• 62题 https://leetcode.cn/problems/unique-paths/description/
• 贪心算法