Merge pull request #2146 from Lozakaka/patch-32

解決跑板問題 + 提供java解法(和卡哥邏輯一致)
This commit is contained in:
程序员Carl
2023-07-11 11:27:33 +08:00
committed by GitHub

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@ -176,6 +176,48 @@ public void dfs(char[][] grid, int i, int j){
dfs(grid,i,j + 1); dfs(grid,i,j + 1);
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);
}
}
}
```
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