更新卡码网0099.岛屿的数量深搜，添加Python3版本

problems/kamacoder/0099.岛屿的数量深搜.md

@@ -185,6 +185,100 @@ int main() {
 
 ### Python
 
+版本一
+
+```python
+direction = [[0, 1], [1, 0], [0, -1], [-1, 0]]  # 四个方向：上、右、下、左
+
+
+def dfs(grid, visited, x, y):
+    """
+    对一块陆地进行深度优先遍历并标记
+    """
+    for i, j in direction:
+        next_x = x + i
+        next_y = y + j
+        # 下标越界，跳过
+        if next_x < 0 or next_x >= len(grid) or next_y < 0 or next_y >= len(grid[0]):
+            continue
+        # 未访问的陆地，标记并调用深度优先搜索
+        if not visited[next_x][next_y] and grid[next_x][next_y] == 1:
+            visited[next_x][next_y] = True
+            dfs(grid, visited, next_x, next_y)
+
+
+if __name__ == '__main__':  
+    # 版本一
+    n, m = map(int, input().split())
+    
+    # 邻接矩阵
+    grid = []
+    for i in range(n):
+        grid.append(list(map(int, input().split())))
+    
+    # 访问表
+    visited = [[False] * m for _ in range(n)]
+    
+    res = 0
+    for i in range(n):
+        for j in range(m):
+            # 判断：如果当前节点是陆地，res+1并标记访问该节点，使用深度搜索标记相邻陆地。
+            if grid[i][j] == 1 and not visited[i][j]:
+                res += 1
+                visited[i][j] = True
+                dfs(grid, visited, i, j)
+    
+    print(res)
+```
+
+版本二
+
+```python
+direction = [[0, 1], [1, 0], [0, -1], [-1, 0]]  # 四个方向：上、右、下、左
+
+
+def dfs(grid, visited, x, y):
+    """
+    对一块陆地进行深度优先遍历并标记
+    """
+    # 与版本一的差别，在调用前增加判断终止条件
+    if visited[x][y] or grid[x][y] == 0:
+        return
+    visited[x][y] = True
+
+    for i, j in direction:
+        next_x = x + i
+        next_y = y + j
+        # 下标越界，跳过
+        if next_x < 0 or next_x >= len(grid) or next_y < 0 or next_y >= len(grid[0]):
+            continue
+        # 由于判断条件放在了方法首部，此处直接调用dfs方法
+        dfs(grid, visited, next_x, next_y)
+
+
+if __name__ == '__main__':
+    # 版本二
+    n, m = map(int, input().split())
+
+    # 邻接矩阵
+    grid = []
+    for i in range(n):
+        grid.append(list(map(int, input().split())))
+
+    # 访问表
+    visited = [[False] * m for _ in range(n)]
+
+    res = 0
+    for i in range(n):
+        for j in range(m):
+            # 判断：如果当前节点是陆地，res+1并标记访问该节点，使用深度搜索标记相邻陆地。
+            if grid[i][j] == 1 and not visited[i][j]:
+                res += 1
+                dfs(grid, visited, i, j)
+
+    print(res)
+```
+
 ### Go
 
 ### Rust