Data commit

Task/Arithmetic-numbers/Go/arithmetic-numbers.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+    "fmt"
+    "math"
+    "rcu"
+    "sort"
+)
+
+func main() {
+    arithmetic := []int{1}
+    primes := []int{}
+    limit := int(1e6)
+    for n := 3; len(arithmetic) < limit; n++ {
+        divs := rcu.Divisors(n)
+        if len(divs) == 2 {
+            primes = append(primes, n)
+            arithmetic = append(arithmetic, n)
+        } else {
+            mean := float64(rcu.SumInts(divs)) / float64(len(divs))
+            if mean == math.Trunc(mean) {
+                arithmetic = append(arithmetic, n)
+            }
+        }
+    }
+    fmt.Println("The first 100 arithmetic numbers are:")
+    rcu.PrintTable(arithmetic[0:100], 10, 3, false)
+
+    for _, x := range []int{1e3, 1e4, 1e5, 1e6} {
+        last := arithmetic[x-1]
+        lastc := rcu.Commatize(last)
+        fmt.Printf("\nThe %sth arithmetic number is: %s\n", rcu.Commatize(x), lastc)
+        pcount := sort.SearchInts(primes, last) + 1
+        if !rcu.IsPrime(last) {
+            pcount--
+        }
+        comp := x - pcount - 1 // 1 is not composite
+        compc := rcu.Commatize(comp)
+        fmt.Printf("The count of such numbers <= %s which are composite is %s.\n", lastc, compc)
+    }
+}