摘要：
There are a number of spherical balloons spread in two-dimensional space. For each balloon, provided input is the start and end coordinates of the hor 阅读全文
摘要：
Given a collection of intervals, find the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping. Note: Exam 阅读全文
摘要：
Given a non-negative integer num represented as a string, remove k digits from the number so that the new number is the smallest possible. Note: The l 阅读全文