Island Counter

Given a grid consisting of '1' (land) and '0' (water), calculate the number of islands in the grid. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. Assume that all four edges of the grid are surrounded by water. Input: A 2D character grid Output: The number of islands Examples Example 1: Input: [["1","1","0","0","0"], ["1","1","0","0","0"], ["0","0","1","0","0"], ["0","0","0","1","1"]] Output: 3 Example 2: Input: [["1","1","1","1","0"], ["1","1","0","1","0"], ["1","1","0","0","0"], ["0","0","0","0","0"]] Output: 1 Constraints The input is a 2D grid with dimensions m x n. 1 <= m, n <= 300 Example Input [["1","1","0","0","0"],["1","1","0","0","0"],["0","0","1","0","0"],["0","0","0","1","1"]]