下面这个链接有比较全的leetcode题目包括锁的
http://www.cnblogs.com/grandyang/p/4606334.html
https://leetcode.com/problems/binary-tree-upside-down/
http://blog.csdn.net/xudli/article/details/42362441
https://leetcode.com/problems/read-n-characters-given-read4/
http://blog.csdn.net/xudli/article/details/42458865
https://leetcode.com/problems/read-n-characters-given-read4-ii-call-multiple-times/
http://blog.csdn.net/xudli/article/details/43225571
https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters/
http://blog.csdn.net/xudli/article/details/43222593
https://leetcode.com/problems/one-edit-distance/
http://blog.csdn.net/xudli/article/details/42340867
https://leetcode.com/problems/missing-ranges/
http://blog.csdn.net/yangliuy/article/details/46502541
https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/
http://blog.csdn.net/xudli/article/details/42290269
https://leetcode.com/problems/two-sum-iii-data-structure-design/
http://blog.csdn.net/xudli/article/details/42290251
https://leetcode.com/problems/reverse-words-in-a-string-ii/
http://www.cnblogs.com/dolphin0520/p/3700019.html
https://leetcode.com/problems/shortest-word-distance/
http://blog.csdn.net/xudli/article/details/48766955
https://leetcode.com/problems/shortest-word-distance-ii/
http://nb4799.neu.edu/wordpress/?p=1028
https://leetcode.com/problems/shortest-word-distance-iii/
http://www.cnblogs.com/easonliu/p/4784826.html
https://leetcode.com/problems/strobogrammatic-number/
http://www.cnblogs.com/grandyang/p/5196960.html
http://www.tangjikai.com/algorithms/leetcode-246-strobogrammatic-number
https://leetcode.com/problems/strobogrammatic-number-ii/
http://www.cnblogs.com/grandyang/p/5200919.html
http://www.cnblogs.com/airwindow/p/4804054.html
https://leetcode.com/problems/strobogrammatic-number-iii/
http://www.cnblogs.com/grandyang/p/5203228.html
https://leetcode.com/problems/group-shifted-strings/
http://www.cnblogs.com/airwindow/p/4806168.html
https://leetcode.com/problems/count-univalue-subtrees/
http://blog.csdn.net/pointbreak1/article/details/48998407
https://leetcode.com/problems/flatten-2d-vector/
http://blog.csdn.net/pointbreak1/article/details/48823513
https://leetcode.com/problems/meeting-rooms/
http://blog.csdn.net/sbitswc/article/details/49068503
https://leetcode.com/problems/meeting-rooms/
方法很好
http://blog.csdn.net/sbitswc/article/details/49068625
https://leetcode.com/problems/factor-combinations/
方法不错
http://www.cnblogs.com/airwindow/p/4822572.html
https://leetcode.com/problems/verify-preorder-sequence-in-binary-search-tree/
http://www.meetqun.com/thread-10674-1-1.html (递归)
http://www.thinksaas.cn/topics/0/397/397305.html （非递归，constant space）
https://leetcode.com/problems/paint-house/
http://www.cnblogs.com/easonliu/p/4784858.html
https://leetcode.com/problems/3sum-smaller/
好题
http://www.cnblogs.com/airwindow/p/4802521.html
https://leetcode.com/problems/graph-valid-tree/
https://segmentfault.com/a/1190000003791051
http://blog.csdn.net/dm_vincent/article/details/7655764 （并查集）
https://leetcode.com/problems/paint-house-ii/
http://www.cnblogs.com/easonliu/p/4784858.html
https://leetcode.com/problems/palindrome-permutation/
http://www.cnblogs.com/anne-vista/p/4831003.html (一样的，用map或者set)
https://leetcode.com/problems/palindrome-permutation-ii/
http://www.cnblogs.com/airwindow/p/4806012.html
https://leetcode.com/problems/alien-dictionary/
好，DFS（toposort）or BFS(based on indegree)
http://www.cnblogs.com/jcliBlogger/p/4758761.html
https://leetcode.com/problems/closest-binary-search-tree-value/
http://www.cnblogs.com/Dylan-Java-NYC/p/5204357.html
https://leetcode.com/problems/encode-and-decode-strings/
利用长度，巧妙
http://www.cnblogs.com/easonliu/p/4784912.html
https://leetcode.com/problems/closest-binary-search-tree-value-ii/
利用堆
http://blog.csdn.net/xudli/article/details/48752907
https://leetcode.com/problems/paint-fence/
题目见
http://www.cnblogs.com/easonliu/p/4784886.html
更清楚的说明
https://leetcode.com/discuss/71756/explanation-of-dp-o-n-time-complexity-o-1-space-complexity
https://leetcode.com/problems/find-the-celebrity/
http://www.cnblogs.com/easonliu/p/4785253.html
https://leetcode.com/problems/wiggle-sort/
http://blog.csdn.net/xudli/article/details/48749155
https://leetcode.com/problems/zigzag-iterator/
http://blog.csdn.net/xudli/article/details/48749219
https://leetcode.com/problems/inorder-successor-in-bst/
http://www.jianshu.com/p/218f686d6494
https://leetcode.com/problems/walls-and-gates/
https://segmentfault.com/a/1190000003906674
https://leetcode.com/problems/unique-word-abbreviation/
http://blog.csdn.net/xudli/article/details/48860911
https://leetcode.com/problems/word-pattern-ii/
好
http://www.cnblogs.com/jcliBlogger/p/4870514.html
https://leetcode.com/problems/flip-game/
http://www.aichengxu.com/view/77156
https://leetcode.com/problems/flip-game-ii/
下面有题目，但是解法有bug（递归之后没有恢复）
http://www.cnblogs.com/yrbbest/p/5043682.html
正确的解法在这里：
https://leetcode.com/discuss/64344/theory-matters-from-backtracking-128ms-to-dp-0ms
https://leetcode.com/problems/best-meeting-point/
好
http://blog.csdn.net/pointbreak1/article/details/49422265
https://leetcode.com/problems/binary-tree-longest-consecutive-sequence/
还行
http://blog.csdn.net/xudli/article/details/49493401
https://leetcode.com/problems/smallest-rectangle-enclosing-black-pixels/
以下O(mn)
http://blog.csdn.net/xudli/article/details/49738267
以下O(m log n + n log m)
https://leetcode.com/discuss/68246/c-java-python-binary-search-solution-with-explanation
http://www.cnblogs.com/jcliBlogger/p/4948140.html （一样的原理）
https://leetcode.com/problems/number-of-islands-ii/
下面介绍了QuickFind, QuickUnion的区别
http://www.cnblogs.com/EdwardLiu/p/5087633.html
下面有路径压缩：
https://leetcode.com/discuss/69572/easiest-java-solution-with-explanations
https://leetcode.com/problems/range-sum-query-2d-mutable/
不错
https://segmentfault.com/a/1190000004238792
https://leetcode.com/problems/sparse-matrix-multiplication/
http://blog.csdn.net/xiaohei00000/article/details/50429791
是基于以下讨论
https://leetcode.com/discuss/71968/regular-28-ms-math-solution-6-8-lines
https://leetcode.com/problems/binary-tree-vertical-order-traversal/
http://blog.csdn.net/qq508618087/article/details/50760661
https://leetcode.com/problems/shortest-distance-from-all-buildings/
http://www.cnblogs.com/grandyang/p/5297683.html
其实是借鉴了以下，但是我还是不明白怎么保证所有都联通
https://leetcode.com/discuss/74453/36-ms-c-solution
下面的倒是验证了所有都联通
https://segmentfault.com/a/1190000004187914
https://leetcode.com/problems/generalized-abbreviation/
解法很多很全
http://www.cnblogs.com/grandyang/p/5261569.html
https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/
解法很清爽，并查集
https://segmentfault.com/a/1190000004224298
https://leetcode.com/problems/maximum-size-subarray-sum-equals-k/
http://blog.csdn.net/jmspan/article/details/51247447
https://leetcode.com/problems/largest-bst-subtree/
http://www.cnblogs.com/grandyang/p/5188938.html
https://leetcode.com/problems/nested-list-weight-sum/
http://www.cnblogs.com/grandyang/p/5340305.html
https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/
好
http://www.cnblogs.com/grandyang/p/5351347.html
https://leetcode.com/problems/moving-average-from-data-stream/
http://www.cnblogs.com/grandyang/p/5450001.html
https://leetcode.com/problems/design-tic-tac-toe/
解法2好
http://www.cnblogs.com/grandyang/p/5467118.html
https://leetcode.com/problems/android-unlock-patterns/
http://www.cnblogs.com/grandyang/p/5541012.html
https://leetcode.com/problems/design-snake-game/
http://www.cnblogs.com/grandyang/p/5558033.html
https://leetcode.com/problems/line-reflection/
http://blog.csdn.net/qq508618087/article/details/51756981
https://leetcode.com/problems/rearrange-string-k-distance-apart/
http://blog.csdn.net/qq508618087/article/details/51762258
https://leetcode.com/problems/logger-rate-limiter/
http://blog.csdn.net/jmspan/article/details/51697104
https://leetcode.com/problems/sort-transformed-array/
http://blog.csdn.net/qq508618087/article/details/51700774
https://leetcode.com/problems/bomb-enemy/
http://blog.csdn.net/qq508618087/article/details/51705806
http://blog.csdn.net/jmspan/article/details/51708425
https://leetcode.com/problems/design-hit-counter/
http://blog.csdn.net/jmspan/article/details/51738164
https://leetcode.com/problems/nested-list-weight-sum-ii/
http://blog.csdn.net/jmspan/article/details/51747784
https://leetcode.com/problems/find-leaves-of-binary-tree/
http://blog.csdn.net/jmspan/article/details/51760985
https://leetcode.com/problems/plus-one-linked-list/
http://blog.csdn.net/qq508618087/article/details/51779701
https://leetcode.com/problems/range-addition/
http://blog.csdn.net/jmspan/article/details/51787011 （第二种的好方法我也想到了哈哈）
https://leetcode.com/problems/design-phone-directory/
http://www.cnblogs.com/grandyang/p/5735205.html
https://leetcode.com/problems/valid-word-abbreviation
http://www.cnblogs.com/grandyang/p/5930369.html
本身题目比较简单，但是文章最后提到的前面那道 Generalized Abbreviation的解法却非常有意思：
http://www.cnblogs.com/grandyang/p/5261569.html
另外看到一个好的解法：
即把"i12iz4n"这样的缩写转换成"i.{12}iz.{4}n"
1 public boolean validWordAbbreviation(String word, String abbr) {
2 return word.matches(abbr.replaceAll("[1-9]\\d*", ".{$0}"));
3 }
https://leetcode.com/problems/minimum-unique-word-abbreviation
http://www.cnblogs.com/grandyang/p/5935836.html
解法一般，用缩写去轮询比较。
http://www.cnblogs.com/easonliu/p/4852129.html
这里的方法稍好一些，通过Hashmap来存储abbreviation.
https://leetcode.com/problems/sentence-screen-fitting
http://blog.csdn.net/mcf171/article/details/52770093
http://www.cnblogs.com/reboot329/p/5947854.html