378. Kth Smallest Element in a Sorted Matrix
Question Given an n x n matrix where each of the rows and columns is sorted in ascending order, return the kth smallest element in the matrix. Note that it is the kth smallest element in the sorted order, not the kth distinct element. You must find a solution with a memory complexity better than O(n2). Example 1: Input: matrix = [[1,5,9],[10,11,13],[12,13,15]], k = 8 Output: 13 Explanation: The elements in the matrix are [1,5,9,10,11,12,13,13,15], and the 8th smallest number is 13 Example 2: Input: matrix = [[-5]], k = 1 Output: -5 Constraints: n == matrix.length == matrix[i].length 1 My Solution My solution is to an vertical sweep of the matrix to find the kth smallest element.I keep a track of current element index in ith row and traverse through these to find smallest in all the rows till I find the kth element. worst case, O(n^2). Optimal Solution Optimal Solution is to perform lowerbound binary search on the matrix using low first element and high as last el...