java.lang.Object
g3601_3700.s3648_minimum_sensors_to_cover_grid.Solution

public class Solution extends Object
3648 - Minimum Sensors to Cover Grid.

Medium

You are given n × m grid and an integer k.

A sensor placed on cell (r, c) covers all cells whose Chebyshev distance from (r, c) is at most k.

The Chebyshev distance between two cells (r1, c1) and (r2, c2) is max(|r1 \u2212 r2|,|c1 \u2212 c2|).

Your task is to return the minimum number of sensors required to cover every cell of the grid.

Example 1:

Input: n = 5, m = 5, k = 1

Output: 4

Explanation:

Placing sensors at positions (0, 3), (1, 0), (3, 3), and (4, 1) ensures every cell in the grid is covered. Thus, the answer is 4.

Example 2:

Input: n = 2, m = 2, k = 2

Output: 1

Explanation:

With k = 2, a single sensor can cover the entire 2 * 2 grid regardless of its position. Thus, the answer is 1.

Constraints:

  • 1 <= n <= 103
  • 1 <= m <= 103
  • 0 <= k <= 103
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • minSensors

      public int minSensors(int n, int m, int k)