func ncat(n []uint64) uint64 {
var rd []uint64
for i := len(n) - 1; i >= 0; i-- {
rd = append(rd, euler.NtoD(n[i])...)
}
return euler.DtoN(rd)
}
func pandigital(n uint64) bool {
ndigits := euler.NtoD(n)
var dc []int
dc = make([]int, len(ndigits)+1)
for i := range ndigits {
d := euler.NtoD(ndigits[i])
for j := range d {
if d[j] == 0 || d[j] > uint64(len(ndigits)) {
return false
}
dc[d[j]]++
}
}
for i := 1; i <= len(ndigits); i++ {
if dc[i] != 1 {
return false
}
}
return true
}
func nthdigit(n uint64) uint64 {
var size uint64 = 1
var length uint64 = 1
var digits uint64 = 1
for n >= digits+9*size*length {
digits += 9 * size * length
size *= 10
length++
}
number := size + ((n - digits) / length)
position := (n - digits) % length
return euler.NtoD(number)[length-1-position]
}
func main() {
var factmap [10]uint64
var total uint64
for i := uint64(1); i < 10; i++ {
factmap[i] = euler.Factorial(i)
}
for i := uint64(3); i < 10000000; i++ {
if i == sum(apply(euler.Factorial, euler.NtoD(i))) {
total += i
}
}
fmt.Printf("32 %d\n", total)
}
func main() {
search:
for i := uint64(1000); i < 10000-(3330*2); i++ {
if i == 1487 {
continue search
}
if !euler.IsPrime(i) {
continue search
}
if !euler.IsPrime(i + 3330) {
continue search
}
if !euler.IsPrime(i + 2*3330) {
continue search
}
if !euler.IsPerm(euler.NtoD(i), euler.NtoD(i+3330)) {
continue search
}
if !euler.IsPerm(euler.NtoD(i), euler.NtoD(i+3330*2)) {
continue search
}
fmt.Printf("49 %d%d%d\n", i, i+3330, i+3330*2)
}
}
func main() {
var sum uint64
digits := euler.NtoD(9876543210)
firstprimes := []uint64{2, 3, 5, 7, 11, 13, 17}
numperms := euler.Factorial(uint64(len(digits)))
search:
for j := uint64(0); j < numperms; j++ {
d := euler.NthPerm(j, digits)
for i := range firstprimes {
if euler.DtoN(d[i+1:i+4])%firstprimes[i] != 0 {
continue search
}
}
sum += euler.DtoN(d)
}
fmt.Printf("43 %d\n", sum)
}
func main() {
var count uint64
var sum uint64
nextcandidate:
for i := uint64(11); count < 11; i++ {
d := euler.NtoD(i)
dlen := len(d)
for j := 0; j < len(d); j++ {
a := euler.DtoN(d[j:dlen])
b := euler.DtoN(d[0 : dlen-j])
if !euler.IsPrime(a) || !euler.IsPrime(b) {
continue nextcandidate
}
}
count++
sum += i
}
fmt.Printf("%d\n", sum)
}
func rot(n uint64) (uint64, bool) {
d := euler.NtoD(n)
d = append(d[len(d):], d[:len(d)]...)
return euler.DtoN(d), d[0] > 0
}