Initial data commit

Task/Metallic-ratios/Go/metallic-ratios.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+    "fmt"
+    "math/big"
+)
+
+var names = [10]string{"Platinum", "Golden", "Silver", "Bronze", "Copper",
+    "Nickel", "Aluminium", "Iron", "Tin", "Lead"}
+
+func lucas(b int64) {
+    fmt.Printf("Lucas sequence for %s ratio, where b = %d:\n", names[b], b)
+    fmt.Print("First 15 elements: ")
+    var x0, x1 int64 = 1, 1
+    fmt.Printf("%d, %d", x0, x1)
+    for i := 1; i <= 13; i++ {
+        x2 := b*x1 + x0
+        fmt.Printf(", %d", x2)
+        x0, x1 = x1, x2
+    }
+    fmt.Println()
+}
+
+func metallic(b int64, dp int) {
+    x0, x1, x2, bb := big.NewInt(1), big.NewInt(1), big.NewInt(0), big.NewInt(b)
+    ratio := big.NewRat(1, 1)
+    iters := 0
+    prev := ratio.FloatString(dp)
+    for {
+        iters++
+        x2.Mul(bb, x1)
+        x2.Add(x2, x0)
+        this := ratio.SetFrac(x2, x1).FloatString(dp)
+        if prev == this {
+            plural := "s"
+            if iters == 1 {
+                plural = " "
+            }
+            fmt.Printf("Value to %d dp after %2d iteration%s: %s\n\n", dp, iters, plural, this)
+            return
+        }
+        prev = this
+        x0.Set(x1)
+        x1.Set(x2)
+    }
+}
+
+func main() {
+    for b := int64(0); b < 10; b++ {
+        lucas(b)
+        metallic(b, 32)
+    }
+    fmt.Println("Golden ratio, where b = 1:")
+    metallic(1, 256)
+}