200. 岛屿数量

中等

题目描述

解法：使用深度优先的思想，不断找相邻为 1 的坐标

class Solution {
    public int numIslands(char[][] grid) {
        int res = 0;
        for(int row = 0;row < grid.length;row++) {
        	for(int col = 0;col < grid[0].length;col++) {
        		if(grid[row][col] == '1') {
        			res++;
        			find(grid,row,col);
        		}else {
        			continue;
        		}
        	}
        }
        return res;
    }

	public void find(char[][] grid, int row, int col) {
		if(row >= 0 && col >= 0 && row < grid.length && col < grid[0].length && grid[row][col] == '1') {
			grid[row][col] = '2';
			// 上下左右
			find(grid,row - 1,col);
			find(grid,row + 1,col);
			find(grid,row,col - 1);
			find(grid,row,col + 1);
		}
		return;
	}
}