Percolation/Bond percolation: Difference between revisions
Added Kotlin
(Added haskell version) |
(Added Kotlin) |
||
Line 768:
"p=10/10 -> 0.0000"
</pre>
=={{header|Kotlin}}==
{{trans|C}}
<lang scala>// version 1.2.10
import java.util.Random
val rand = Random()
const val RAND_MAX = 32767
// cell states
const val FILL = 1
const val RWALL = 2 // right wall
const val BWALL = 4 // bottom wall
val x = 10
val y = 10
var grid = IntArray(x * (y + 2))
var cells = 0
var end = 0
var m = 0
var n = 0
fun makeGrid(p: Double) {
val thresh = (p * RAND_MAX).toInt()
m = x
n = y
grid.fill(0) // clears grid
for (i in 0 until m) grid[i] = BWALL or RWALL
cells = m
end = m
for (i in 0 until y) {
for (j in x - 1 downTo 1) {
val r1 = rand.nextInt(RAND_MAX + 1)
val r2 = rand.nextInt(RAND_MAX + 1)
grid[end++] = (if (r1 < thresh) BWALL else 0) or
(if (r2 < thresh) RWALL else 0)
}
val r3 = rand.nextInt(RAND_MAX + 1)
grid[end++] = RWALL or (if (r3 < thresh) BWALL else 0)
}
}
fun showGrid() {
for (j in 0 until m) print("+--")
println("+")
for (i in 0..n) {
print(if (i == n) " " else "|")
for (j in 0 until m) {
print(if ((grid[i * m + j + cells] and FILL) != 0) "[]" else " ")
print(if ((grid[i * m + j + cells] and RWALL) != 0) "|" else " ")
}
println()
if (i == n) return
for (j in 0 until m) {
print(if ((grid[i * m + j + cells] and BWALL) != 0) "+--" else "+ ")
}
println("+")
}
}
fun fill(p: Int): Boolean {
if ((grid[p] and FILL) != 0) return false
grid[p] = grid[p] or FILL
if (p >= end) return true // success: reached bottom row
return (((grid[p + 0] and BWALL) == 0) && fill(p + m)) ||
(((grid[p + 0] and RWALL) == 0) && fill(p + 1)) ||
(((grid[p - 1] and RWALL) == 0) && fill(p - 1)) ||
(((grid[p - m] and BWALL) == 0) && fill(p - m))
}
fun percolate(): Boolean {
var i = 0
while (i < m && !fill(cells + i)) i++
return i < m
}
fun main(args: Array<String>) {
makeGrid(0.5)
percolate()
showGrid()
println("\nrunning $x x $y grids 10,000 times for each p:")
for (p in 1..9) {
var cnt = 0
val pp = p / 10.0
for (i in 0 until 10_000) {
makeGrid(pp)
if (percolate()) cnt++
}
println("p = %3g: %.4f".format(pp, cnt.toDouble() / 10_000))
}
}</lang>
Sample output:
<pre>
+--+--+--+--+--+--+--+--+--+--+
|[]|[] [] [] [] []| | | | |
+--+--+--+--+--+ +--+ + + +
| | | | []| |
+--+--+--+--+--+ + +--+ + +
| | | | |[] []| |
+ + + + + +--+--+--+--+--+
| | | [] [] []| | |
+--+--+ + +--+--+--+--+--+ +
| | |[] []| | | |
+--+--+ + + + +--+ +--+--+
| | | |[]|[]| | | |
+--+ +--+--+ +--+--+ + + +
| | | []| | | | |
+--+ + + + +--+--+ + + +
| | |[] []| | |
+ +--+--+ +--+ +--+ + +--+
| | [] | | | |
+ + +--+ + +--+--+--+--+ +
| [] | | | |
+ +--+--+ + +--+--+ +--+ +
[]
running 10 x 10 grids 10,000 times for each p:
p = 0.100000: 1.0000
p = 0.200000: 1.0000
p = 0.300000: 0.9968
p = 0.400000: 0.9184
p = 0.500000: 0.5047
p = 0.600000: 0.0828
p = 0.700000: 0.0034
p = 0.800000: 0.0000
p = 0.900000: 0.0000
</pre>
=={{header|Perl 6}}==
{{works with|Rakudo|2017.02}}
| |||