Data commit

Task/Generate-random-chess-position/Scala/generate-random-chess-position.scala

@@ -0,0 +1,73 @@
+import scala.math.abs
+import scala.util.Random
+
+object RandomFen extends App {
+  val rand = new Random
+
+  private def createFen = {
+    val grid = Array.ofDim[Char](8, 8)
+
+    def placeKings(grid: Array[Array[Char]]): Unit = {
+      var r1, c1, r2, c2 = 0
+      do {
+        r1 = rand.nextInt(8)
+        c1 = rand.nextInt(8)
+        r2 = rand.nextInt(8)
+        c2 = rand.nextInt(8)
+      } while (r1 == r2 || abs(r1 - r2) <= 1 || abs(c1 - c2) <= 1)
+      grid(r1)(c1) = 'K'
+      grid(r2)(c2) = 'k'
+    }
+
+    def placePieces(grid: Array[Array[Char]],
+                    pieces: String,
+                    isPawn: Boolean): Unit = {
+      val numToPlace = rand.nextInt(pieces.length)
+
+      for (n <- 0 until numToPlace) {
+        var r, c = 0
+        do {
+          r = rand.nextInt(8)
+          c = rand.nextInt(8)
+        } while (grid(r)(c) != 0 || (isPawn && (r == 7 || r == 0)))
+        grid(r)(c) = pieces(n)
+      }
+    }
+
+    def toFen(grid: Array[Array[Char]]) = {
+      val fen = new StringBuilder
+      var countEmpty = 0
+      for (r <- grid.indices) {
+        for (c <- grid.indices) {
+          val ch = grid(r)(c)
+          print(f"${if (ch == 0) '.' else ch}%2c ")
+          if (ch == 0) countEmpty += 1
+          else {
+            if (countEmpty > 0) {
+              fen.append(countEmpty)
+              countEmpty = 0
+            }
+            fen.append(ch)
+          }
+        }
+        if (countEmpty > 0) {
+          fen.append(countEmpty)
+          countEmpty = 0
+        }
+        fen.append("/")
+        println()
+      }
+      fen.append(" w - - 0 1").toString
+    }
+
+    placeKings(grid)
+    placePieces(grid, "PPPPPPPP", isPawn = true)
+    placePieces(grid, "pppppppp", isPawn = true)
+    placePieces(grid, "RNBQBNR", isPawn = false)
+    placePieces(grid, "rnbqbnr", isPawn = false)
+    toFen(grid)
+  }
+
+  println(createFen)
+
+}