10/20/2016
tag: DP 95. Unique Binary Search Trees II; Unique Binary Search Trees I; 300. Longest Increasing Subsequence; Guess Number Higher or Lower II; Longest Increasing Subsequence; Ugly Number II
10/22/2016
tag: DP 264. Ugly Number II; 221. Maximal Square, House Robber II
10/23/2016
tag: DP 152. Maximum Product Subarray; 53. Maximum Subarray; 304. Range Sum Query 2D - Immutable
10/26/2016
tag: backtracking 93. Restore IP Addresses; Longest Palindromic Substring; 89. Gray Code; 79. Word Search(记得重做)
02/21/2017
163; *159; 158; 244; 245; 246; 247; 248; 249;
02/22/2017
250; 251; 254(错了); 255; 256; 265；270(错了);
02/23/2017
LintCode: binary search + copybook(hard)