Data commit

Task/Lah-numbers/Go/lah-numbers.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+    "fmt"
+    "math/big"
+)
+
+func main() {
+    limit := 100
+    last := 12
+    unsigned := true
+    l := make([][]*big.Int, limit+1)
+    for n := 0; n <= limit; n++ {
+        l[n] = make([]*big.Int, limit+1)
+        for k := 0; k <= limit; k++ {
+            l[n][k] = new(big.Int)
+        }
+        l[n][n].SetInt64(int64(1))
+        if n != 1 {
+            l[n][1].MulRange(int64(2), int64(n))
+        }
+    }
+    var t big.Int
+    for n := 1; n <= limit; n++ {
+        for k := 1; k <= n; k++ {
+            t.Mul(l[n][1], l[n-1][1])
+            t.Quo(&t, l[k][1])
+            t.Quo(&t, l[k-1][1])
+            t.Quo(&t, l[n-k][1])
+            l[n][k].Set(&t)
+            if !unsigned && (n%2 == 1) {
+                l[n][k].Neg(l[n][k])
+            }
+        }
+    }
+    fmt.Println("Unsigned Lah numbers: l(n, k):")
+    fmt.Printf("n/k")
+    for i := 0; i <= last; i++ {
+        fmt.Printf("%10d ", i)
+    }
+    fmt.Printf("\n--")
+    for i := 0; i <= last; i++ {
+        fmt.Printf("-----------")
+    }
+    fmt.Println()
+    for n := 0; n <= last; n++ {
+        fmt.Printf("%2d ", n)
+        for k := 0; k <= n; k++ {
+            fmt.Printf("%10d ", l[n][k])
+        }
+        fmt.Println()
+    }
+    fmt.Println("\nMaximum value from the l(100, *) row:")
+    max := new(big.Int).Set(l[limit][0])
+    for k := 1; k <= limit; k++ {
+        if l[limit][k].Cmp(max) > 0 {
+            max.Set(l[limit][k])
+        }
+    }
+    fmt.Println(max)
+    fmt.Printf("which has %d digits.\n", len(max.String()))
+}