Find Kth Largest XOR Coordinate Value

arraydivide and conquerbit manipulation

You are given a 2D matrix of size m x n , consisting of non-negative integers. You are also given an integer k .

The value of coordinate (a, b) of the matrix is the XOR of all matrix[i][j] where 0 <= i <= a < m and 0 <= j <= b < n (0-indexed) .

Find the k ^th largest value (1-indexed) of all the coordinates of matrix .

Example 1

Input: matrix = [[5,2],[1,6]], k = 1
Output: 7
The value of coordinate (0,1) is 5 XOR 2 = 7, which is the largest value.

Example 2

Input: matrix = [[5,2],[1,6]], k = 2
Output: 5
The value of coordinate (0,0) is 5 = 5, which is the 2nd largest value.

Example 3

Input: matrix = [[5,2],[1,6]], k = 3
Output: 4
The value of coordinate (1,0) is 5 XOR 1 = 4, which is the 3rd largest value.

m == matrix.length

n == matrix[i].length

1 <= m, n <= 1000

0 <= matrix[i][j] <= 10 ^6

1 <= k <= m * n

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicDivide and Conquer