题解 | #岛屿数量#

import java.util.*;


public class Solution {

    public int solve (char[][] grid) {
        int number = 0;
        for (int i = 0; i < grid.length; i++) {
            for (int j = 0; j < grid[i].length; j++) {
                if (grid[i][j] == '1') {
                    dfs(grid, i, j);
                    number++;
                }
            }
        }
        return number;
    }

    /**
         * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
         *
         * 判断岛屿数量
         * @param grid char字符型二维数组
         * @return int整型
         */
    public void dfs(char[][] grid, int i, int j) {
        // 终止条件
        if (i < 0 || j < 0 || i > grid.length-1 || j > grid[0].length-1 || grid[i][j] == '0') {
            return;
        }
        // 将每一个遍历到的岛屿节点改为 ‘0’
        if (grid[i][j] == '1') {
            grid[i][j] = '0';
        }
        dfs(grid, i - 1, j);
        dfs(grid, i + 1, j);
        dfs(grid, i, j - 1);
        dfs(grid, i, j + 1);
    }
}