GeeksforGeeks Divide&Conquer

http://www.geeksforgeeks.org/closest-pair-of-points-onlogn-implementation/

http://www.geeksforgeeks.org/closest-pair-of-points/  复杂度证明

http://www.geeksforgeeks.org/divide-and-conquer-set-2-karatsuba-algorithm-for-fast-multiplication/

http://www.geeksforgeeks.org/find-a-peak-in-a-given-array/

http://www.geeksforgeeks.org/program-to-count-number-of-set-bits-in-an-big-array/