Several interview questions:
1. C4_32_PairSumK: update a O(N) solution
2. C4_47_OccurrenceFinder find occurrence times of a given number in array
3. C4_48_ABArray find the N numbers can be divide by A or B
4. C1_48_SquareCheck check if a number is square of other number
5. C4_47_LargestSlopeLine find the largest slope line when given points
6. C5_21_ClosestLargerF find the most closest larger number of mid in tree