200. 島嶼數量
給你一個由 '1'(陸地)和 '0'(水)組成的的二維網格,請你計算網格中島嶼的數量。島嶼總是被水包圍,並且每座島嶼只能由水平方向和/或豎直方向上相鄰的陸地連接形成。
此外,你可以假設該網格的四條邊均被水包圍。
示例 1:
輸入:grid = [
["1","1","1","1","0"],
["1","1","0","1","0"],
["1","1","0","0","0"],
["0","0","0","0","0"]
]
輸出:1
示例 2:
輸入:grid = [
["1","1","0","0","0"],
["1","1","0","0","0"],
["0","0","1","0","0"],
["0","0","0","1","1"]
]
輸出:3
提示:
m == grid.length
n == grid[i].length
1 <= m, n <= 300
grid[i][j] 的值爲 '0' 或 '1'