diff --git a/problems/0695.岛屿的最大面积.md b/problems/0695.岛屿的最大面积.md index 186f044c..3dd181a3 100644 --- a/problems/0695.岛屿的最大面积.md +++ b/problems/0695.岛屿的最大面积.md @@ -390,6 +390,147 @@ class Solution: if 0 <= new_x < len(grid) and 0 <= new_y < len(grid[0]): self.dfs(grid, visited, new_x, new_y) ``` + +### Rust + +dfs: 版本一 + +```rust +impl Solution { + const DIRECTIONS: [(i32, i32); 4] = [(0, 1), (1, 0), (-1, 0), (0, -1)]; + + pub fn max_area_of_island(grid: Vec>) -> i32 { + let mut visited = vec![vec![false; grid[0].len()]; grid.len()]; + + let mut res = 0; + for (i, nums) in grid.iter().enumerate() { + for (j, &num) in nums.iter().enumerate() { + if !visited[i][j] && num == 1 { + let mut count = 1; + visited[i][j] = true; + Self::dfs(&grid, &mut visited, (i as i32, j as i32), &mut count); + res = res.max(count); + } + } + } + + res + } + + pub fn dfs( + grid: &[Vec], + visited: &mut [Vec], + (x, y): (i32, i32), + count: &mut i32, + ) { + for (dx, dy) in Self::DIRECTIONS { + let (nx, ny) = (x + dx, y + dy); + if nx < 0 || nx >= grid.len() as i32 || ny < 0 || ny >= grid[0].len() as i32 { + continue; + } + let (nx, ny) = (nx as usize, ny as usize); + if !visited[nx][ny] && grid[nx][ny] == 1 { + visited[nx][ny] = true; + *count += 1; + Self::dfs(grid, visited, (nx as i32, ny as i32), count); + } + } + } +} +``` + +dfs: 版本二 + +```rust +impl Solution { + const DIRECTIONS: [(i32, i32); 4] = [(0, 1), (1, 0), (-1, 0), (0, -1)]; + + pub fn max_area_of_island(grid: Vec>) -> i32 { + let mut visited = vec![vec![false; grid[0].len()]; grid.len()]; + + let mut res = 0; + for (i, nums) in grid.iter().enumerate() { + for (j, &num) in nums.iter().enumerate() { + if !visited[i][j] && num == 1 { + let mut count = 0; + Self::dfs(&grid, &mut visited, (i as i32, j as i32), &mut count); + res = res.max(count); + } + } + } + + res + } + + pub fn dfs( + grid: &[Vec], + visited: &mut [Vec], + (x, y): (i32, i32), + count: &mut i32, + ) { + if visited[x as usize][y as usize] || grid[x as usize][y as usize] == 0 { + return; + } + visited[x as usize][y as usize] = true; + *count += 1; + for (dx, dy) in Self::DIRECTIONS { + let (nx, ny) = (x + dx, y + dy); + if nx < 0 || nx >= grid.len() as i32 || ny < 0 || ny >= grid[0].len() as i32 { + continue; + } + Self::dfs(grid, visited, (nx, ny), count); + } + } +} +``` + +bfs: + +```rust +use std::collections::VecDeque; +impl Solution { + const DIRECTIONS: [(i32, i32); 4] = [(0, 1), (1, 0), (-1, 0), (0, -1)]; + + pub fn max_area_of_island(grid: Vec>) -> i32 { + let mut visited = vec![vec![false; grid[0].len()]; grid.len()]; + + let mut res = 0; + for (i, nums) in grid.iter().enumerate() { + for (j, &num) in nums.iter().enumerate() { + if !visited[i][j] && num == 1 { + let mut count = 0; + Self::bfs(&grid, &mut visited, (i as i32, j as i32), &mut count); + res = res.max(count); + } + } + } + + res + } + + pub fn bfs(grid: &[Vec], visited: &mut [Vec], (x, y): (i32, i32), count: &mut i32) { + let mut queue = VecDeque::new(); + queue.push_back((x, y)); + visited[x as usize][y as usize] = true; + *count += 1; + 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; + } + let (nx, ny) = (nx as usize, ny as usize); + if !visited[nx][ny] && grid[nx][ny] == 1 { + visited[nx][ny] = true; + queue.push_back((nx as i32, ny as i32)); + *count += 1; + } + } + } + } +} +``` +