Implement regular expression matching with support for ‘.’ and ‘*’.
A robot is located at the top-left corner of a m x n grid (marked ‘Start’ in the diagram below). The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked ‘Finish’ in the diagram below). How many possible […]
Given a target number, and a series of candidate numbers, print out all combinations, so that the sum of candidate numbers equals to the target.