Coding Round 2
Mid-Level
programming
LeetCode #200 - Number of Islands
Background: Given a 2D grid consisting of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by water.
Problem Statement: Given an m x n grid, return the number of islands.
Typed Signature:
Example 1:
Input: grid = ["11110", "11010", "11000", "00000"]
Output: 1
Explanation: There is one island.
Example 2:
Input: grid = ["11000", "11000", "00100", "00011"]
Output: 3
Explanation: There are three islands.
Constraints: m == grid.length, n == grid[i].length, 1 <= m, n <= 300.
Problem Statement: Given an m x n grid, return the number of islands.
Typed Signature:
def num_islands(grid: List[List[str]]) -> int:Example 1:
Input: grid = ["11110", "11010", "11000", "00000"]
Output: 1
Explanation: There is one island.
Example 2:
Input: grid = ["11000", "11000", "00100", "00011"]
Output: 3
Explanation: There are three islands.
Constraints: m == grid.length, n == grid[i].length, 1 <= m, n <= 300.
Suggested Answer