Problem #49

Problem link
Solution:

package main

import (
    "strings"
    "strconv"
)

func main() {
    arr := make([]bool, 10000)
    prime := 2
    finished := false
    var i int
    for !finished {
        for i = 2 * prime; i < 10000; i += prime {
            arr[i] = true
        }
        //next prime
        for i = prime + 1; i < 10000 && arr[i]; i++ {
        }
        if i < 10000 {
            prime = i
        } else {
            finished = true
        }
    }
outer:
    for i := 1000; i < len(arr); i++ {
        for j := i + 1; j < len(arr); j++ {
            if i != 1487 && !arr[i] && !arr[j] && isPerm(i, j) && 2*j-i < 10000 && !arr[2*j-i] && isPerm(i, 2*j-i) {
                print(i)
                print(j)
                print(2*j - i)
                break outer
            }
        }
    }
    println()
}

func isPerm(i1, i2 int) bool {
    s1, s2 := strconv.Itoa(i1), strconv.Itoa(i2)
    for i := 0; i < len(s1); i++ {
        //we need a cross check for repetition of numbers like in 1049 1499 comparison
        if !strings.Contains(s1, s2[i:i+1]) || !strings.Contains(s2, s1[i:i+1]) {
            return false
        }
    }
    return true
}

Result: 296962999629
Time: 0m0.420s