Trie/ Segment Tree/ Binary Index Tree/ Graph/ Union Find

(1) Segment Tree Build, Query, Modify (lintcode 201/202/203)
(2) Interval minimum number (lintcode 205) Similar: Segment Tree Build II (lintcode 439)
(3) Interval sum II (lintcode 207)
(4) Segment Tree Query II
(5) Count Smaller Number before itself (lintcode 249) Similar (leetcode 314 Count smaller number after itself)
(6) Count of Range sum(leetcode 327)

(7) implement Trie (leetcode 208)
(8) Add and Search Word (leetcode 211)
(9) Word Search II (leetcode 212)
(10) Palindrome Pairs (leetcode 336)

(11) Reconstruct literary (leetcode 332, graph edge)
(12) clone graph (leetcode 133)
(13) Minimum height tree (leetcode 310)
(14) Course Schedule II (leetcode 210)
(15) Alien Dictionary (leetcode 269)

(16) Number of islands (leetcode 200) number of islandsII (leetcode 305)
(17) Number of connected components in undirected graph (leetcode 323)
(18) Graph valid tree (leetcode 261)