利用堆栈：

http://oj.leetcode.com/problems/evaluate-reverse-polish-notation/

http://oj.leetcode.com/problems/longest-valid-parentheses/ （也可以用一维数组，贪心）

http://oj.leetcode.com/problems/valid-parentheses/

http://oj.leetcode.com/problems/largest-rectangle-in-histogram/

特别注意细节：http://oj.leetcode.com/problems/trapping-rain-water/



多种数据结构：

http://oj.leetcode.com/problems/lru-cache/

http://oj.leetcode.com/problems/substring-with-concatenation-of-all-words/
(注意遍历方法）

HASH：http://oj.leetcode.com/problems/longest-consecutive-sequence/



简单编程：

http://oj.leetcode.com/problems/longest-common-prefix/

http://oj.leetcode.com/problems/string-to-integer-atoi/ (分析，控制语句）



排序 & 查找：

二分查找：http://oj.leetcode.com/problems/search-a-2d-matrix/

二分查找进阶：http://oj.leetcode.com/problems/search-for-a-range/

二分查找应用：http://oj.leetcode.com/problems/sqrtx/

二分查找应用：http://oj.leetcode.com/problems/search-insert-position/

二分查找变种：http://oj.leetcode.com/problems/search-in-rotated-sorted-array/

二分查找变种：http://oj.leetcode.com/problems/search-in-rotated-sorted-array-ii/



简单数学：

http://oj.leetcode.com/problems/pascals-triangle/

http://oj.leetcode.com/problems/pascals-triangle-ii/

http://oj.leetcode.com/problems/powx-n/

http://oj.leetcode.com/problems/reverse-integer/

http://oj.leetcode.com/problems/plus-one/

http://oj.leetcode.com/problems/unique-paths/

http://oj.leetcode.com/problems/palindrome-number/

http://oj.leetcode.com/problems/permutation-sequence/

http://oj.leetcode.com/problems/merge-intervals/

http://oj.leetcode.com/problems/valid-number/

http://oj.leetcode.com/problems/climbing-stairs/

http://oj.leetcode.com/problems/roman-to-integer/

http://oj.leetcode.com/problems/integer-to-roman/

http://oj.leetcode.com/problems/divide-two-integers/

区间：http://oj.leetcode.com/problems/insert-interval/



大数的数学运算：

http://oj.leetcode.com/problems/add-binary/

http://oj.leetcode.com/problems/add-two-numbers/



数组：

http://oj.leetcode.com/problems/remove-element/

http://oj.leetcode.com/problems/merge-sorted-array/

http://oj.leetcode.com/problems/first-missing-positive/

http://oj.leetcode.com/problems/spiral-matrix/

http://oj.leetcode.com/problems/spiral-matrix-ii/

http://oj.leetcode.com/problems/rotate-image/

遍历技巧：http://oj.leetcode.com/problems/container-with-most-water/

http://oj.leetcode.com/problems/two-sum/

http://oj.leetcode.com/problems/3sum/

http://oj.leetcode.com/problems/3sum-closest/

http://oj.leetcode.com/problems/4sum/

http://oj.leetcode.com/problems/set-matrix-zeroes/

用好标记数组：http://oj.leetcode.com/problems/valid-sudoku/

http://oj.leetcode.com/problems/next-permutation/

http://oj.leetcode.com/problems/word-search/

http://oj.leetcode.com/problems/remove-duplicates-from-sorted-array/

http://oj.leetcode.com/problems/remove-duplicates-from-sorted-array-ii/

http://oj.leetcode.com/problems/sort-colors/



暴力方法/细节实现：

http://oj.leetcode.com/problems/max-points-on-a-line/



链表：

归并排序：http://oj.leetcode.com/problems/sort-list/

插入排序：http://oj.leetcode.com/problems/insertion-sort-list/

反转、插入：http://oj.leetcode.com/problems/reorder-list/

检测是否有环：http://oj.leetcode.com/problems/linked-list-cycle/

确定链表环的起点：http://oj.leetcode.com/problems/linked-list-cycle-ii/

Deep Copy 带有随机指针的链表：http://oj.leetcode.com/problems/copy-list-with-random-pointer/

链表细节：http://oj.leetcode.com/problems/rotate-list/

http://oj.leetcode.com/problems/remove-duplicates-from-sorted-list/

删除细节：http://oj.leetcode.com/problems/remove-duplicates-from-sorted-list-ii/

http://oj.leetcode.com/problems/partition-list/

http://oj.leetcode.com/problems/swap-nodes-in-pairs/

Merge 两个链表：http://oj.leetcode.com/problems/merge-two-sorted-lists/

Merge 多链表：http://oj.leetcode.com/problems/merge-k-sorted-lists/

细节：http://oj.leetcode.com/problems/reverse-nodes-in-k-group/

http://oj.leetcode.com/problems/remove-nth-node-from-end-of-list/

http://oj.leetcode.com/problems/reverse-linked-list-ii/



二叉树遍历：递归 & 非递归

http://oj.leetcode.com/problems/same-tree/

前序：http://oj.leetcode.com/problems/binary-tree-preorder-traversal/

中序：http://oj.leetcode.com/problems/binary-tree-inorder-traversal/

后序：http://oj.leetcode.com/problems/binary-tree-postorder-traversal/

遍历变种：http://oj.leetcode.com/problems/sum-root-to-leaf-numbers/

遍历变种：http://oj.leetcode.com/problems/path-sum/

遍历变种：http://oj.leetcode.com/problems/path-sum-ii/

遍历变种：http://oj.leetcode.com/problems/maximum-depth-of-binary-tree/

遍历变种：http://oj.leetcode.com/problems/minimum-depth-of-binary-tree/

重建二叉树：http://oj.leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/

重建二叉树：http://oj.leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal/

层次遍历变种：http://oj.leetcode.com/problems/binary-tree-zigzag-level-order-traversal/

遍历变种：http://oj.leetcode.com/problems/symmetric-tree/

遍历应用：http://oj.leetcode.com/problems/binary-tree-maximum-path-sum/

遍历应用：http://oj.leetcode.com/problems/balanced-binary-tree/

遍历应用：http://oj.leetcode.com/problems/recover-binary-search-tree/

遍历应用：http://oj.leetcode.com/problems/flatten-binary-tree-to-linked-list/

level遍历：http://oj.leetcode.com/problems/binary-tree-level-order-traversal/

level 遍历：http://oj.leetcode.com/problems/binary-tree-level-order-traversal-ii/

level 遍历变种：http://oj.leetcode.com/problems/populating-next-right-pointers-in-each-node/

level 遍历变种：http://oj.leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/



问题分析/智商/细节：

http://oj.leetcode.com/problems/single-number/

http://oj.leetcode.com/problems/single-number-ii/

http://oj.leetcode.com/problems/candy/ ？

http://oj.leetcode.com/problems/gas-station/



动态规划：

http://oj.leetcode.com/problems/triangle/ （最短路径）

http://oj.leetcode.com/problems/subsets/ （另一种形式）

http://oj.leetcode.com/problems/subsets-ii/

http://oj.leetcode.com/problems/edit-distance/ （经典）

http://oj.leetcode.com/problems/word-break/

http://oj.leetcode.com/problems/word-break-ii/

http://oj.leetcode.com/problems/unique-binary-search-trees/ （动态规划避免递归）

http://oj.leetcode.com/problems/unique-paths-ii/

http://oj.leetcode.com/problems/scramble-string/

http://oj.leetcode.com/problems/palindrome-partitioning/

http://oj.leetcode.com/problems/palindrome-partitioning-ii/

http://oj.leetcode.com/problems/interleaving-string/

http://oj.leetcode.com/problems/distinct-subsequences/

http://oj.leetcode.com/problems/decode-ways/

http://oj.leetcode.com/problems/gray-code/

http://oj.leetcode.com/problems/minimum-path-sum/



回溯：

http://oj.leetcode.com/problems/combinations/

http://oj.leetcode.com/problems/generate-parentheses/

http://oj.leetcode.com/problems/combination-sum/

http://oj.leetcode.com/problems/combination-sum-ii/

http://oj.leetcode.com/problems/sudoku-solver/

经典N皇后：http://oj.leetcode.com/problems/n-queens/

http://oj.leetcode.com/problems/n-queens-ii/

http://oj.leetcode.com/problems/letter-combinations-of-a-phone-number/



贪心：

http://oj.leetcode.com/problems/best-time-to-buy-and-sell-stock/

http://oj.leetcode.com/problems/jump-game/

http://oj.leetcode.com/problems/jump-game-ii/

http://oj.leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/

http://oj.leetcode.com/problems/best-time-to-buy-and-sell-stock-iii/

http://oj.leetcode.com/problems/maximum-subarray/

http://oj.leetcode.com/problems/minimum-window-substring/

http://oj.leetcode.com/problems/maximal-rectangle/

http://oj.leetcode.com/problems/longest-substring-without-repeating-characters/



分治 & 递归：

http://oj.leetcode.com/problems/unique-binary-search-trees-ii/

http://oj.leetcode.com/problems/restore-ip-addresses/ （时间复杂度有限，递归满足）

http://oj.leetcode.com/problems/permutations/

http://oj.leetcode.com/problems/permutations-ii/

http://oj.leetcode.com/problems/convert-sorted-array-to-binary-search-tree/

http://oj.leetcode.com/problems/convert-sorted-list-to-binary-search-tree/

http://oj.leetcode.com/problems/median-of-two-sorted-arrays/

http://oj.leetcode.com/problems/validate-binary-search-tree/



字符串：

http://oj.leetcode.com/problems/count-and-say/

http://oj.leetcode.com/problems/implement-strstr/ （子串查找）

http://oj.leetcode.com/problems/anagrams/

http://oj.leetcode.com/problems/text-justification/ (细节）

http://oj.leetcode.com/problems/simplify-path/ （基础控制语句 if-else-for）

http://oj.leetcode.com/problems/multiply-strings/

http://oj.leetcode.com/problems/regular-expression-matching/

http://oj.leetcode.com/problems/wildcard-matching/

http://oj.leetcode.com/problems/longest-palindromic-substring/

http://oj.leetcode.com/problems/zigzag-conversion/

http://oj.leetcode.com/problems/length-of-last-word/

http://oj.leetcode.com/problems/valid-palindrome/



图：

深搜/广搜：http://oj.leetcode.com/problems/clone-graph/



搜索 & 遍历：

http://oj.leetcode.com/problems/word-ladder/

http://oj.leetcode.com/problems/word-ladder-ii/

广搜：http://oj.leetcode.com/problems/surrounded-regions/