Data commit

Task/N-queens-problem/Kotlin/n-queens-problem.kotlin

@@ -0,0 +1,30 @@
+// version 1.1.3
+
+var count = 0
+var c = IntArray(0)
+var f = ""
+
+fun nQueens(row: Int, n: Int) {
+    outer@ for (x in 1..n) {
+        for (y in 1..row - 1) {
+            if (c[y] == x) continue@outer
+            if (row - y == Math.abs(x - c[y])) continue@outer
+        }
+        c[row] = x
+        if (row < n) nQueens(row + 1, n)
+        else if (++count == 1) f = c.drop(1).map { it - 1 }.toString()
+    }
+}
+
+fun main(args: Array<String>) {
+   for (n in 1..14) {
+       count = 0
+       c = IntArray(n + 1)
+       f = ""
+       nQueens(1, n)
+       println("For a $n x $n board:")
+       println("  Solutions = $count")
+       if (count > 0) println("  First is $f")
+       println()
+   }
+}