diff --git a/problems/0200.岛屿数量.深搜版.md b/problems/0200.岛屿数量.深搜版.md index 6d42162a..c30ace19 100644 --- a/problems/0200.岛屿数量.深搜版.md +++ b/problems/0200.岛屿数量.深搜版.md @@ -176,6 +176,48 @@ public void dfs(char[][] grid, int i, int j){ dfs(grid,i,j + 1); dfs(grid,i,j - 1); } +``` +```java +//graph - dfs (和卡哥的代碼邏輯一致) +class Solution { + boolean[][] visited; + int dir[][] = { + {0, 1}, //right + {1, 0}, //down + {-1, 0}, //up + {0, -1} //left + }; + public int numIslands(char[][] grid) { + int count = 0; + visited = new boolean[grid.length][grid[0].length]; + + for(int i = 0; i < grid.length; i++){ + for(int j = 0; j < grid[0].length; j++){ + if(visited[i][j] == false && grid[i][j] == '1'){ + count++; + dfs(grid, i, j); + } + } + } + return count; + } + + private void dfs(char[][]grid, int x, int y){ + if(visited[x][y] == true || grid[x][y] == '0') + return; + + visited[x][y] = true; + + for(int i = 0; i < 4; i++){ + int nextX = x + dir[i][0]; + int nextY = y + dir[i][1]; + if(nextX < 0 || nextY < 0 || nextX >= grid.length || nextY >= grid[0].length) + continue; + dfs(grid, nextX, nextY); + } + } +} +```