Minimum Number of Days to Disconnect Island

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Problem Statement

You are given an m x n binary grid grid where 1 represents land and 0 represents water. An island is a maximal 4-directionally (horizontal or vertical) connected group of 1 's.

The grid is said to be connected if we have exactly one island , otherwise is said disconnected .

In one day, we are allowed to change any single land cell (1) into a water cell (0) .

Return the minimum number of days to disconnect the grid .

Examples

Example 1

Input: grid = [[0,1,1,0],[0,1,1,0],[0,0,0,0]]
Output: 2
We need at least 2 days to get a disconnected grid.
Change land grid[1][1] and grid[0][2] to water and get 2 disconnected island.

Example 2

Input: grid = [[1,1]]
Output: 2
Grid of full water is also disconnected ([[1,1]] -> [[0,0]]), 0 islands.

Constraints

m == grid.length

n == grid[i].length

1 <= m, n <= 30

grid[i][j] is either 0 or 1 .

😤

Hard

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicDepth-First Search