Merge pull request #2725 from cyxiwai/kama99

更新并补充了kama0099.岛屿的数量dfs和bfs的版本，附有详细注释

problems/kamacoder/0099.岛屿的数量广搜.md

@@ -191,10 +191,57 @@ int main() {
 ### Java 
 
 ```java
+import java.util.*;
 
+public class Main {
+    public static int[][] dir = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};//下右上左逆时针遍历
 
+    public static void bfs(int[][] grid, boolean[][] visited, int x, int y) {
+        Queue<pair> queue = new LinkedList<pair>();//定义坐标队列，没有现成的pair类，在下面自定义了
+        queue.add(new pair(x, y));
+        visited[x][y] = true;//遇到入队直接标记为优先，
+        // 否则出队时才标记的话会导致重复访问，比如下方节点会在右下顺序的时候被第二次访问入队
+        while (!queue.isEmpty()) {
+            int curX = queue.peek().first;
+            int curY = queue.poll().second;//当前横纵坐标
+            for (int i = 0; i < 4; i++) {
+                //顺时针遍历新节点next，下面记录坐标
+                int nextX = curX + dir[i][0];
+                int nextY = curY + dir[i][1];
+                if (nextX < 0 || nextX >= grid.length || nextY < 0 || nextY >= grid[0].length) {
+                    continue;
+                }//去除越界部分
+                if (!visited[nextX][nextY] && grid[nextX][nextY] == 1) {
+                    queue.add(new pair(nextX, nextY));
+                    visited[nextX][nextY] = true;//逻辑同上
+                }
+            }
+        }
+    }
 
-
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int m = sc.nextInt();
+        int n = sc.nextInt();
+        int[][] grid = new int[m][n];
+        boolean[][] visited = new boolean[m][n];
+        int ans = 0;
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                grid[i][j] = sc.nextInt();
+            }
+        }
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                if (!visited[i][j] && grid[i][j] == 1) {
+                    ans++;
+                    bfs(grid, visited, i, j);
+                }
+            }
+        }
+        System.out.println(ans);
+    }
+}
 ```
 
 

problems/kamacoder/0099.岛屿的数量深搜.md

@@ -182,7 +182,52 @@ int main() {
 ## 其他语言版本
 
 ### Java 
+```java
+import java.util.Scanner;
 
+public class Main {
+    public static int[][] dir ={{0,1},{1,0},{-1,0},{0,-1}};
+    public static void dfs(boolean[][] visited,int x,int y ,int [][]grid)
+    {
+        for (int i = 0; i < 4; i++) {
+            int nextX=x+dir[i][0];
+            int nextY=y+dir[i][1];
+            if(nextY<0||nextX<0||nextX>= grid.length||nextY>=grid[0].length)
+                continue;
+            if(!visited[nextX][nextY]&&grid[nextX][nextY]==1)
+            {
+                visited[nextX][nextY]=true;
+                dfs(visited,nextX,nextY,grid);
+            }
+        }
+    }
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int m= sc.nextInt();
+        int n = sc.nextInt();
+        int[][] grid = new int[m][n];
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                grid[i][j]=sc.nextInt();
+            }
+        }
+        boolean[][]visited =new boolean[m][n];
+        int ans = 0;
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                if(!visited[i][j]&&grid[i][j]==1)
+                {
+                    ans++;
+                    visited[i][j]=true;
+                    dfs(visited,i,j,grid);
+                }
+            }
+        }
+        System.out.println(ans);
+    }
+}
+
+```
 ### Python
 
 版本一