func C041() (interface{}, error) {
max := 0
upperLimit := 987654321
primes := utils.PrimesLowerThan(upperLimit)
for _, prime := range primes {
if utils.IsPandigital(strconv.Itoa(prime)) {
if prime > max {
max = prime
// fmt.Println(prime)
}
}
}
return max, nil
}
func C038() (interface{}, error) {
max := 0
for left := 1; left < 10000; left++ {
output := ""
for right := 1; right < 9 && len(output) < 9; right++ {
output += strconv.Itoa(left * right)
}
if len(output) == 9 && utils.IsPandigital(output) {
nb, _ := strconv.Atoi(output)
// fmt.Println(left, nb)
if nb > max {
max = nb
}
}
}
return max, nil
}
func C032() (interface{}, error) {
products := map[int]bool{}
for a := 1; a < 9000; a++ {
for b := a + 1; b < 9000; b++ {
product := a * b
nbStr := fmt.Sprintf("%d%d%d", a, b, product)
length := len(nbStr)
if length > 9 {
break
}
if length != 9 {
continue
}
if utils.IsPandigital(nbStr) {
products[product] = true
}
}
}
sum := 0
for product := range products {
sum += product
}
return sum, nil
}