From 1bc7ca5f8f364e5ae560854d32e6b96cb74408ec Mon Sep 17 00:00:00 2001
From: fwqaaq <fwqaaq@gmail.com>
Date: Mon, 21 Aug 2023 23:15:44 +0800
Subject: [PATCH] =?UTF-8?q?Update=201020.=E9=A3=9E=E5=9C=B0=E7=9A=84?=
 =?UTF-8?q?=E6=95=B0=E9=87=8F.md?=
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---
 problems/1020.飞地的数量.md | 45 ++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/problems/1020.飞地的数量.md b/problems/1020.飞地的数量.md
index 1ef0796d..29c237e5 100644
--- a/problems/1020.飞地的数量.md
+++ b/problems/1020.飞地的数量.md
@@ -530,6 +530,51 @@ impl Solution {
 }
 ```
 
+bfs:
+
+```rust
+use std::collections::VecDeque;
+impl Solution {
+    const DIRECTIONS: [(i32, i32); 4] = [(0, 1), (1, 0), (-1, 0), (0, -1)];
+
+    pub fn num_enclaves(mut grid: Vec<Vec<i32>>) -> i32 {
+        for i in 0..grid.len() {
+            for j in 0..grid[0].len() {
+                if (i == 0 || i == grid.len() - 1 || j == 0 || j == grid[0].len() - 1)
+                    && grid[i][j] == 1
+                {
+                    // Self::dfs(&mut grid, (i as i32, j as i32));
+                    Self::bfs(&mut grid, (i as i32, j as i32));
+                }
+            }
+        }
+        grid.iter()
+            .map(|nums| nums.iter().filter(|&&num| num == 1).count() as i32)
+            .sum()
+    }
+
+    pub fn bfs(grid: &mut [Vec<i32>], (x, y): (i32, i32)) {
+        let mut queue = VecDeque::new();
+        queue.push_back((x, y));
+        grid[x as usize][y as usize] = 0;
+        while let Some((cur_x, cur_y)) = queue.pop_front() {
+            for (dx, dy) in Self::DIRECTIONS {
+                let (nx, ny) = (cur_x + dx, cur_y + dy);
+                if nx < 0 || nx >= grid.len() as i32 || ny < 0 || ny >= grid[0].len() as i32 {
+                    continue;
+                }
+
+                if grid[nx as usize][ny as usize] == 0 {
+                    continue;
+                }
+                queue.push_back((nx, ny));
+                grid[nx as usize][ny as usize] = 0;
+            }
+        }
+    }
+}
+```
+
 
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