86 lines
1.4 KiB
Go
86 lines
1.4 KiB
Go
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bufio"
|
||
|
|
"fmt"
|
||
|
|
"os"
|
||
|
|
"sort"
|
||
|
|
)
|
||
|
|
|
||
|
|
var (
|
||
|
|
grid [][]byte = make([][]byte, 0)
|
||
|
|
width, height int
|
||
|
|
)
|
||
|
|
|
||
|
|
func isMin(x, y int) bool {
|
||
|
|
var left, right, top, bottom byte
|
||
|
|
if x == 0 {
|
||
|
|
left = '9'
|
||
|
|
} else {
|
||
|
|
left = grid[x-1][y]
|
||
|
|
}
|
||
|
|
if x == height-1 {
|
||
|
|
right = '9'
|
||
|
|
} else {
|
||
|
|
right = grid[x+1][y]
|
||
|
|
}
|
||
|
|
if y == 0 {
|
||
|
|
top = '9'
|
||
|
|
} else {
|
||
|
|
top = grid[x][y-1]
|
||
|
|
}
|
||
|
|
if y == width-1 {
|
||
|
|
bottom = '9'
|
||
|
|
} else {
|
||
|
|
bottom = grid[x][y+1]
|
||
|
|
}
|
||
|
|
return grid[x][y] < top && grid[x][y] < bottom && grid[x][y] < left && grid[x][y] < right
|
||
|
|
}
|
||
|
|
|
||
|
|
type Min struct {
|
||
|
|
x, y int
|
||
|
|
}
|
||
|
|
|
||
|
|
var minimums []Min
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
s := bufio.NewScanner(os.Stdin)
|
||
|
|
s.Scan()
|
||
|
|
width = len(s.Text())
|
||
|
|
for {
|
||
|
|
line := make([]byte, width)
|
||
|
|
for i, ch := range s.Text() {
|
||
|
|
line[i] = byte(ch)
|
||
|
|
}
|
||
|
|
grid = append(grid, line)
|
||
|
|
if !s.Scan() {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
}
|
||
|
|
height = len(grid)
|
||
|
|
|
||
|
|
for y := 0; y < width; y++ {
|
||
|
|
for x := 0; x < height; x++ {
|
||
|
|
if isMin(x, y) {
|
||
|
|
minimums = append(minimums, Min{x, y})
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
basins := make([]int, 0)
|
||
|
|
for _, m := range minimums {
|
||
|
|
basins = append(basins, computeBasinSize(m.x, m.y))
|
||
|
|
}
|
||
|
|
sort.Ints(basins)
|
||
|
|
basins = basins[len(basins)-3:]
|
||
|
|
fmt.Println(basins[0] * basins[1] * basins[2])
|
||
|
|
}
|
||
|
|
|
||
|
|
func computeBasinSize(x, y int) int {
|
||
|
|
if x < 0 || x >= height || y < 0 || y >= width || grid[x][y] == '9' {
|
||
|
|
return 0
|
||
|
|
}
|
||
|
|
grid[x][y] = '9'
|
||
|
|
return 1 + computeBasinSize(x-1, y) + computeBasinSize(x+1, y) + computeBasinSize(x, y-1) + computeBasinSize(x, y+1)
|
||
|
|
}
|