func Euler023(limit int) int {
abNums := []int{}
for i := 1; i < limit; i++ {
d := utils.Divisors(i)
if utils.Sum(d[:len(d)-1]) > i {
abNums = append(abNums, i)
}
}
possibleSums := make(map[int]bool)
for _, a1 := range abNums {
for _, a2 := range abNums {
if a1+a2 < limit {
possibleSums[a1+a2] = true
}
}
}
sum := 0
for i := 0; i < limit; i++ {
if !possibleSums[i] {
sum += i
}
}
return sum
}
func d(n int) (sum int) {
dn := utils.Divisors(n) //Divisors returns also the number itself at the end of the slice
// so we need to remove it later from loop
dnl := len(dn)
for _, v := range dn[:dnl-1] {
sum += v
}
return sum
}
func Euler012(target int) int {
tNum, i, numDiv := 1, 1, 1
for numDiv < target {
i++
tNum += i
numDiv = len(utils.Divisors(tNum))
}
return tNum
}