Number of Islands

Problem: Number of Islands Given an m x n 2D grid of characters '1' land and '0' water, return the number of islands. An island is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are surrounded by water. Input Format The first line contains two integers m n. The next m lines each contain n characters, either 0 or 1. Characters may be written with or without spaces. Output Format Print one integer: the number of islands. Constraints 1 <= m, n <= 300 grid[i][j] is '0' or '1' Example Input: 4 5 11110 11010 11000 00000 Output: 1 Example Input 4 5 11110 11010 11000 00000 Output 1