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| 1 | +#![allow(dead_code)] |
| 2 | +pub fn oranges_rotting(grid: &mut Vec<Vec<i32>>) -> i32 { |
| 3 | + let rows = grid.len(); |
| 4 | + let cols = grid[0].len(); |
| 5 | + let mut fresh = 0; |
| 6 | + let mut time = 0; |
| 7 | + let mut q = std::collections::VecDeque::new(); |
| 8 | + |
| 9 | + for r in 0..rows { |
| 10 | + for c in 0..cols { |
| 11 | + if grid[r][c] == 1 { |
| 12 | + fresh += 1; |
| 13 | + } |
| 14 | + if grid[r][c] == 2 { |
| 15 | + q.push_back((r, c)); |
| 16 | + } |
| 17 | + } |
| 18 | + } |
| 19 | + |
| 20 | + let directions = [(0, 1), (0, -1), (1, 0), (-1, 0)]; |
| 21 | + |
| 22 | + while !q.is_empty() && fresh > 0 { |
| 23 | + let qlen = q.len(); |
| 24 | + for _ in 0..qlen { |
| 25 | + let (r, c) = q.pop_front().unwrap(); |
| 26 | + |
| 27 | + for (dr, dc) in &directions { |
| 28 | + let row = r as i32 + dr; |
| 29 | + let col = c as i32 + dc; |
| 30 | + if row >= 0 |
| 31 | + && col >= 0 |
| 32 | + && row < rows as i32 |
| 33 | + && col < cols as i32 |
| 34 | + && grid[row as usize][col as usize] == 1 |
| 35 | + { |
| 36 | + grid[row as usize][col as usize] = 2; |
| 37 | + q.push_back((row as usize, col as usize)); |
| 38 | + fresh -= 1; |
| 39 | + } |
| 40 | + } |
| 41 | + } |
| 42 | + time += 1; |
| 43 | + } |
| 44 | + |
| 45 | + if fresh == 0 { |
| 46 | + time |
| 47 | + } else { |
| 48 | + -1 |
| 49 | + } |
| 50 | +} |
| 51 | + |
| 52 | +#[test] |
| 53 | +fn test_oranges_rotting() { |
| 54 | + let mut grid = vec![vec![2, 1, 1], vec![1, 1, 0], vec![0, 1, 1]]; |
| 55 | + assert_eq!(oranges_rotting(&mut grid), 4); |
| 56 | + let mut grid = vec![vec![2, 1, 1], vec![0, 1, 1], vec![1, 0, 1]]; |
| 57 | + assert_eq!(oranges_rotting(&mut grid), -1); |
| 58 | + let mut grid = vec![vec![0, 2]]; |
| 59 | + assert_eq!(oranges_rotting(&mut grid), 0); |
| 60 | +} |
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