94 lines
2.4 KiB
Java
94 lines
2.4 KiB
Java
//给你一个由 '1'（陆地）和 '0'（水）组成的的二维网格，请你计算网格中岛屿的数量。
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//
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// 岛屿总是被水包围，并且每座岛屿只能由水平方向和/或竖直方向上相邻的陆地连接形成。
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//
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// 此外，你可以假设该网格的四条边均被水包围。
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//
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//
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//
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// 示例 1：
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//
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//
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//输入：grid = [
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// ["1","1","1","1","0"],
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// ["1","1","0","1","0"],
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// ["1","1","0","0","0"],
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// ["0","0","0","0","0"]
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//]
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//输出：1
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//
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//
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// 示例 2：
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//
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//
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//输入：grid = [
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// ["1","1","0","0","0"],
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// ["1","1","0","0","0"],
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// ["0","0","1","0","0"],
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// ["0","0","0","1","1"]
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//]
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//输出：3
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//
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//
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//
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//
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// 提示：
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//
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//
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// m == grid.length
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// n == grid[i].length
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// 1 <= m, n <= 300
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// grid[i][j] 的值为 '0' 或 '1'
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//
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// Related Topics 深度优先搜索 广度优先搜索 并查集 数组 矩阵
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// 👍 1212 👎 0
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package leetcode.editor.cn;
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import java.util.Arrays;
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import java.util.LinkedList;
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import java.util.List;
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import java.util.Queue;
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//200:岛屿数量
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public class NumberOfIslands {
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public static void main(String[] args) {
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//测试代码
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Solution solution = new NumberOfIslands().new Solution();
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System.out.println(solution.numIslands(new char[][]{
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{'1', '1', '1', '1', '0'},
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{'1', '1', '0', '1', '0'},
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{'1', '1', '0', '0', '0'},
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{'0', '0', '0', '0', '0'}
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}));
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}
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//力扣代码
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//leetcode submit region begin(Prohibit modification and deletion)
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class Solution {
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public int numIslands(char[][] grid) {
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int count = 0;
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for(int i = 0; i < grid.length; i++) {
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for(int j = 0; j < grid[0].length; j++) {
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if(grid[i][j] == '1'){
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dfs(grid, i, j);
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count++;
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}
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}
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}
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return count;
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}
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private void dfs(char[][] grid, int x, int y){
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if(x < 0 || y < 0 || x >= grid.length || y >= grid[0].length || grid[x][y] == '0') {
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return;
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}
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grid[x][y] = '0';
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dfs(grid, x + 1, y);
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dfs(grid, x, y + 1);
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dfs(grid, x - 1, y);
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dfs(grid, x, y - 1);
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}
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}
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//leetcode submit region end(Prohibit modification and deletion)
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} |