package main
import (
"fmt"
"strconv"
)
// Function to check primality
func isPrime(n int64) bool {
if n < 2 {
return false
}
if n%2 == 0 && n != 2 {
return false
}
for i := int64(3); i*i <= n; i += 2 {
if n%i == 0 {
return false
}
}
return true
}
// Concatenate two integers
func concat(a, b int) int64 {
s := strconv.Itoa(a) + strconv.Itoa(b)
num, _ := strconv.ParseInt(s, 10, 64)
return num
}
func main() {
limit := 12 // you can increase this
var primes []int
// Generate primes up to limit
for i := 2; i <= limit; i++ {
if isPrime(int64(i)) {
primes = append(primes, i)
}
}
// Check pairs
for i := 0; i < len(primes); i++ {
for j := 0; j < len(primes); j++ {
if i == j {
continue // skip same prime if you want
}
num := concat(primes[i], primes[j])
if isPrime(num) {
fmt.Printf("%d + %d -> %d is prime\n", primes[i], primes[j], num)
}
}
}
}
/*
run:
2 + 3 -> 23 is prime
2 + 11 -> 211 is prime
3 + 7 -> 37 is prime
3 + 11 -> 311 is prime
5 + 3 -> 53 is prime
7 + 3 -> 73 is prime
11 + 3 -> 113 is prime
*/
