Overview
Segment tree is a tree data structure for storing intervals, or segments.
Can be used to search the max/min or sum values in a range.
modify = O(log n)
query = O(log n)
build = O(n)
question list
[LintCode] Segment Tree Build
[LintCode] Segment Tree Build II
[LintCode] Segment Tree Modify
[LintCode] Segment Tree Query
[LintCode] Segment Tree Query II