Program to find nth smallest number from a given matrix in Python

Suppose we have a 2D matrix, where each row and column is sorted in non-decreasing order, we have to find the nth smallest number.

So, if the input is like

And n = 4, then the output will be 6.

To solve this, we will follow these steps −

• lst := a new list
• for each row i in matrix, do
  • for each cell j in i, do
    • insert j at the end of lst
• sort the list lst
• return lst[n]

Let us see the following implementation to get better understanding −

Example

 Live Demo

class Solution:    def solve(self, matrix, n):       lst = []       for i in matrix:          for j in i:             lst.append(j)       lst.sort()       return lst[n] ob = Solution() matrix = [ [2, 4, 30], [3, 4, 31], [6, 6, 32] ] n = 4 print(ob.solve(matrix, n))

Input

matrix = [ [2, 4, 30], [3, 4, 31], [6, 6, 32] ] n = 4

Output

6