Kth smallest element in sorted matrix

Question

This is an interview question.

Find the K^th smallest element in a matrix with sorted rows and columns.
Is it correct that the K^th small

Answer 1

Above solution could not handle diagonal condition and can not be applied to below matrix

int arr2[][] = { { 1, 4, 7, 11, 15 }, 
                 { 2, 5, 8, 12, 19 }, 
                 { 3, 6, 9, 16, 22 }, 
                 { 10, 13, 14, 17, 24 },
                 { 18, 21, 23, 26, 30 } }

And k=5

Returning 7 whereas answer is 5