@@ -185,6 +185,77 @@ int main() {
185185
186186### Java
187187
188+ ``` java
189+ 190+ import java.util.* ;
191+ 192+ public class Main {
193+ private static int count = 0 ;
194+ private static final int [][] dir = {{0 , 1 }, {1 , 0 }, {- 1 , 0 }, {0 , - 1 }}; // 四个方向
195+ 196+ private static void bfs (int [][] grid , int x , int y ) {
197+ Queue<int[]> que = new LinkedList<> ();
198+ que. add(new int []{x, y});
199+ grid[x][y] = 0 ; // 只要加入队列,立刻标记
200+ count++ ;
201+ while (! que. isEmpty()) {
202+ int [] cur = que. poll();
203+ int curx = cur[0 ];
204+ int cury = cur[1 ];
205+ for (int i = 0 ; i < 4 ; i++ ) {
206+ int nextx = curx + dir[i][0 ];
207+ int nexty = cury + dir[i][1 ];
208+ if (nextx < 0 || nextx >= grid. length || nexty < 0 || nexty >= grid[0 ]. length) continue ; // 越界了,直接跳过
209+ if (grid[nextx][nexty] == 1 ) {
210+ que. add(new int []{nextx, nexty});
211+ count++ ;
212+ grid[nextx][nexty] = 0 ; // 只要加入队列立刻标记
213+ }
214+ }
215+ }
216+ }
217+ 218+ public static void main (String [] args ) {
219+ Scanner scanner = new Scanner (System . in);
220+ int n = scanner. nextInt();
221+ int m = scanner. nextInt();
222+ int [][] grid = new int [n][m];
223+ 224+ // 读取网格
225+ for (int i = 0 ; i < n; i++ ) {
226+ for (int j = 0 ; j < m; j++ ) {
227+ grid[i][j] = scanner. nextInt();
228+ }
229+ }
230+ 231+ // 从左侧边,和右侧边向中间遍历
232+ for (int i = 0 ; i < n; i++ ) {
233+ if (grid[i][0 ] == 1 ) bfs(grid, i, 0 );
234+ if (grid[i][m - 1 ] == 1 ) bfs(grid, i, m - 1 );
235+ }
236+ 237+ // 从上边和下边向中间遍历
238+ for (int j = 0 ; j < m; j++ ) {
239+ if (grid[0 ][j] == 1 ) bfs(grid, 0 , j);
240+ if (grid[n - 1 ][j] == 1 ) bfs(grid, n - 1 , j);
241+ }
242+ 243+ count = 0 ;
244+ for (int i = 0 ; i < n; i++ ) {
245+ for (int j = 0 ; j < m; j++ ) {
246+ if (grid[i][j] == 1 ) bfs(grid, i, j);
247+ }
248+ }
249+ 250+ System . out. println(count);
251+ }
252+ }
253+ 254+ 255+ 256+ ```
257+ 258+ 188259### Python
189260``` python
190261from collections import deque
@@ -238,6 +309,97 @@ print(count)
238309```
239310### Go
240311
312+ ``` go
313+ 314+ package main
315+ 316+ import (
317+ " fmt"
318+ )
319+ 320+ var count int
321+ var dir = [4 ][2 ]int {{0 , 1 }, {1 , 0 }, {-1 , 0 }, {0 , -1 }} // 四个方向
322+ 323+ func bfs (grid [][]int , x , y int ) {
324+ queue := [][2 ]int {{x, y}}
325+ grid[x][y] = 0 // 只要加入队列,立刻标记
326+ count++
327+ 328+ for len (queue) > 0 {
329+ cur := queue[0 ]
330+ queue = queue[1 :]
331+ curx , cury := cur[0 ], cur[1 ]
332+ 333+ for i := 0 ; i < 4 ; i++ {
334+ nextx := curx + dir[i][0 ]
335+ nexty := cury + dir[i][1 ]
336+ 337+ if nextx < 0 || nextx >= len (grid) || nexty < 0 || nexty >= len (grid[0 ]) {
338+ continue // 越界了,直接跳过
339+ }
340+ 341+ if grid[nextx][nexty] == 1 {
342+ queue = append (queue, [2 ]int {nextx, nexty})
343+ count++
344+ grid[nextx][nexty] = 0 // 只要加入队列立刻标记
345+ }
346+ }
347+ }
348+ }
349+ 350+ func main () {
351+ var n , m int
352+ fmt.Scan (&n, &m)
353+ 354+ grid := make ([][]int , n)
355+ for i := range grid {
356+ grid[i] = make ([]int , m)
357+ }
358+ 359+ for i := 0 ; i < n; i++ {
360+ for j := 0 ; j < m; j++ {
361+ fmt.Scan (&grid[i][j])
362+ }
363+ }
364+ 365+ // 从左侧边,和右侧边向中间遍历
366+ for i := 0 ; i < n; i++ {
367+ if grid[i][0 ] == 1 {
368+ bfs (grid, i, 0 )
369+ }
370+ if grid[i][m-1 ] == 1 {
371+ bfs (grid, i, m-1 )
372+ }
373+ }
374+ 375+ // 从上边和下边向中间遍历
376+ for j := 0 ; j < m; j++ {
377+ if grid[0 ][j] == 1 {
378+ bfs (grid, 0 , j)
379+ }
380+ if grid[n-1 ][j] == 1 {
381+ bfs (grid, n-1 , j)
382+ }
383+ }
384+ 385+ // 清空之前的计数
386+ count = 0
387+ 388+ // 遍历所有位置
389+ for i := 0 ; i < n; i++ {
390+ for j := 0 ; j < m; j++ {
391+ if grid[i][j] == 1 {
392+ bfs (grid, i, j)
393+ }
394+ }
395+ }
396+ 397+ fmt.Println (count)
398+ }
399+ 400+ 401+ ```
402+ 241403### Rust
242404
243405### Javascript
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