FastPrep
Problem · Matrix

Number of Islands

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Problem statement

Given an array of equal-length strings grid, where '1' represents land and '0' represents water, return the number of islands.

An island is a maximal group of land cells connected horizontally or vertically. Cells outside the matrix are water.

Function

countIslands(grid: String[]) → int

Examples

Example 1

grid = ["11110","11010","11000","00000"]return = 1

All land cells belong to one orthogonally connected component.

Example 2

grid = ["11000","11000","00100","00011"]return = 3

The upper-left block, the center cell, and the lower-right pair form three separate islands.

Example 3

grid = ["000","000"]return = 0

The matrix contains no land cells.

Constraints

  • 1 <= grid.length <= 300
  • 1 <= grid[i].length <= 300
  • Every row has the same length and contains only '0' and '1'.

More Tekion problems

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public int countIslands(String[] grid) {
    // write your code here
}
grid["11110","11010","11000","00000"]
expected1
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