Data commit

Task/Cyclops-numbers/Go/cyclops-numbers.go

@@ -0,0 +1,113 @@
+package main
+
+import (
+    "fmt"
+    "rcu"
+    "strconv"
+    "strings"
+)
+
+func findFirst(list []int) (int, int) {
+    for i, n := range list {
+        if n > 1e7 {
+            return n, i
+        }
+    }
+    return -1, -1
+}
+
+func reverse(s string) string {
+    chars := []rune(s)
+    for i, j := 0, len(chars)-1; i < j; i, j = i+1, j-1 {
+        chars[i], chars[j] = chars[j], chars[i]
+    }
+    return string(chars)
+}
+
+func main() {
+    ranges := [][2]int{
+        {0, 0}, {101, 909}, {11011, 99099}, {1110111, 9990999}, {111101111, 119101111},
+    }
+    var cyclops []int
+    for _, r := range ranges {
+        numDigits := len(fmt.Sprint(r[0]))
+        center := numDigits / 2
+        for i := r[0]; i <= r[1]; i++ {
+            digits := rcu.Digits(i, 10)
+            if digits[center] == 0 {
+                count := 0
+                for _, d := range digits {
+                    if d == 0 {
+                        count++
+                    }
+                }
+                if count == 1 {
+                    cyclops = append(cyclops, i)
+                }
+            }
+        }
+    }
+    fmt.Println("The first 50 cyclops numbers are:")
+    for i, n := range cyclops[0:50] {
+        fmt.Printf("%6s ", rcu.Commatize(n))
+        if (i+1)%10 == 0 {
+            fmt.Println()
+        }
+    }
+    n, i := findFirst(cyclops)
+    ns, is := rcu.Commatize(n), rcu.Commatize(i)
+    fmt.Printf("\nFirst such number > 10 million is %s at zero-based index %s\n", ns, is)
+
+    var primes []int
+    for _, n := range cyclops {
+        if rcu.IsPrime(n) {
+            primes = append(primes, n)
+        }
+    }
+    fmt.Println("\n\nThe first 50 prime cyclops numbers are:")
+    for i, n := range primes[0:50] {
+        fmt.Printf("%6s ", rcu.Commatize(n))
+        if (i+1)%10 == 0 {
+            fmt.Println()
+        }
+    }
+    n, i = findFirst(primes)
+    ns, is = rcu.Commatize(n), rcu.Commatize(i)
+    fmt.Printf("\nFirst such number > 10 million is %s at zero-based index %s\n", ns, is)
+
+    var bpcyclops []int
+    var ppcyclops []int
+    for _, p := range primes {
+        ps := fmt.Sprint(p)
+        split := strings.Split(ps, "0")
+        noMiddle, _ := strconv.Atoi(split[0] + split[1])
+        if rcu.IsPrime(noMiddle) {
+            bpcyclops = append(bpcyclops, p)
+        }
+        if ps == reverse(ps) {
+            ppcyclops = append(ppcyclops, p)
+        }
+    }
+
+    fmt.Println("\n\nThe first 50 blind prime cyclops numbers are:")
+    for i, n := range bpcyclops[0:50] {
+        fmt.Printf("%6s ", rcu.Commatize(n))
+        if (i+1)%10 == 0 {
+            fmt.Println()
+        }
+    }
+    n, i = findFirst(bpcyclops)
+    ns, is = rcu.Commatize(n), rcu.Commatize(i)
+    fmt.Printf("\nFirst such number > 10 million is %s at zero-based index %s\n", ns, is)
+
+    fmt.Println("\n\nThe first 50 palindromic prime cyclops numbers are:\n")
+    for i, n := range ppcyclops[0:50] {
+        fmt.Printf("%9s ", rcu.Commatize(n))
+        if (i+1)%8 == 0 {
+            fmt.Println()
+        }
+    }
+    n, i = findFirst(ppcyclops)
+    ns, is = rcu.Commatize(n), rcu.Commatize(i)
+    fmt.Printf("\n\nFirst such number > 10 million is %s at zero-based index %s\n", ns, is)
+}