Primes which contain only one odd digit: Difference between revisions

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@@ Line 28: / Line 28: @@
     "rcu"
 )
+func allButOneEven(prime int) bool {
+    digits := rcu.Digits(prime, 10)
+    digits = digits[:len(digits)-1]
+    allEven := true
+    for _, d := range digits {
+        if d&1 == 1 {
+            allEven = false
+            break
+        }
+    }
+    return allEven
+}
 func main() {
     const (
         LIMIT      = 999
+        LIMIT2     = 999999
         MAX_DIGITS = 3
     )
@@ Line 37: / Line 51: @@
     var results []int
     for _, prime := range primes[1:] {
-        digits := rcu.Digits(prime, 10)
+        if allButOneEven(prime) {
-        digits = digits[:len(digits)-1]
-        allEven := true
-        for _, d := range digits {
-            if d&1 == 1 {
-                allEven = false
-                break
-            }
-        }
-        if allEven {
             results = append(results, prime)
         }
@@ Line 58: / Line 63: @@
     }
     fmt.Println("\nFound", len(results), "such primes.")
+    primes = rcu.Primes(LIMIT2)
+    count := 0
+    for _, prime := range primes[1:] {
+        if allButOneEven(prime) {
+            count = count + 1
+        }
+    }
+    cs := rcu.Commatize(count)
+    ls := rcu.Commatize(LIMIT2 + 1)
+    fmt.Println("\nThere are", cs, "primes under", ls, "which contain only one odd digit.")
 }</lang>
@@ Line 70: / Line 86: @@
 Found 45 such primes.
+There are 2,560 primes under 1,000,000 which contain only one odd digit.
 </pre>