package top100liked

import (
	"fmt"
	"testing"
)

// https://leetcode.cn/problems/rotting-oranges/?envType=study-plan-v2&envId=top-100-liked

type point struct {
	Row int
	Col int
}

// AC，成绩不错，但是写的比较复杂
// func getFreshOrangesAround(grid [][]int, p point) []point {
// 	m, n := len(grid), len(grid[0])
// 	r, c := p.Row, p.Col
// 	res := []point{}
// 	if r > 0 && grid[r-1][c] == 1 {
// 		res = append(res, point{r - 1, c})
// 	}
// 	if r < m-1 && grid[r+1][c] == 1 {
// 		res = append(res, point{r + 1, c})
// 	}
// 	if c > 0 && grid[r][c-1] == 1 {
// 		res = append(res, point{r, c - 1})
// 	}
// 	if c < n-1 && grid[r][c+1] == 1 {
// 		res = append(res, point{r, c + 1})
// 	}
// 	return res
// }

// func orangesRotting(grid [][]int) int {
// 	m := len(grid)
// 	n := len(grid[0])

// 	queue := []point{}
// 	minutes := 0
// 	for row := range m {
// 		for col := range n {
// 			if grid[row][col] == 2 {
// 				queue = append(queue, point{row, col})
// 				minutes = -1
// 			}
// 		}
// 	}

// 	for len(queue) > 0 {
// 		batch := []point{}
// 		for len(queue) > 0 {
// 			cur := queue[0]
// 			queue = queue[1:]
// 			freshOranges := getFreshOrangesAround(grid, cur)
// 			for _, p := range freshOranges {
// 				grid[p.Row][p.Col] = 2
// 			}
// 			batch = append(batch, freshOranges...)
// 		}
// 		minutes++
// 		queue = batch
// 	}

// 	for row := range m {
// 		for col := range n {
// 			if grid[row][col] == 1 {
// 				return -1
// 			}
// 		}
// 	}

// 	return minutes
// }

func orangesRotting(grid [][]int) int {
	m, n := len(grid), len(grid[0])
	queue := []point{}
	fresh := 0
	for r := range m {
		for c := range n {
			switch grid[r][c] {
			case 2:
				queue = append(queue, point{r, c})
			case 1:
				fresh++
			}
		}
	}
	if fresh == 0 {
		return 0
	}
	minutes := -1
	dirs := []point{{-1, 0}, {1, 0}, {0, -1}, {0, 1}}
	for len(queue) > 0 {
		size := len(queue)
		for range size {
			cur := queue[0]
			queue = queue[1:]
			for _, d := range dirs {
				nr, nc := cur.Row+d.Row, cur.Col+d.Col
				if nr >= 0 && nr < m && nc >= 0 && nc < n && grid[nr][nc] == 1 {
					grid[nr][nc] = 2
					fresh--
					queue = append(queue, point{nr, nc})
				}
			}
		}
		minutes++
	}
	if fresh > 0 {
		return -1
	}
	return minutes
}

func Test1(t *testing.T) {
	input := [][]int{{2, 1, 1}, {1, 1, 0}, {0, 1, 1}}
	fmt.Println(orangesRotting(input))
}

func Test2(t *testing.T) {
	input := [][]int{{2, 1, 1}, {0, 1, 1}, {1, 0, 1}}
	fmt.Println(orangesRotting(input))
}

func Test3(t *testing.T) {
	input := [][]int{{0, 2}}
	fmt.Println(orangesRotting(input))
}