http://www.geeksforgeeks.org/find-if-there-is-a-subarray-with-0-sum/

Kth smallest element in a row-wise and column-wise sorted 2D array | Set 1

http://www.geeksforgeeks.org/kth-smallest-element-in-a-row-wise-and-column-wise-sorted-2d-array-set-1/