Given a collection of intervals, merge all overlapping intervals. For example: Given [1,3],[2,6],[8,10],[15,18], return [1,6],[8,10],[15,18

Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary). You may assume that the intervals

You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). You need to do this in place.

Given a non-negative number represented as an array of digits, add 1 to the number ( increment the number represented by the digits ).