func Solve27() (solution int) {
primes := make(map[int]struct{})
for p := range util.Sieve(10709) {
primes[p] = struct{}{}
}
max := 0
for a := -999; a < 1000; a++ {
for b := -999; b < 1000; b++ {
for n := 0; ; n++ {
form := n*n + a*n + b
if form < 0 || form%2 == 0 {
break
}
_, isPrime := primes[form]
if !isPrime {
if n > max {
max = n
solution = a * b
}
break
}
}
}
}
return
}
func Solve7() (solution int) {
primes := util.Sieve(105000)
i := 1
for p := range primes {
if i == 10001 {
return p
}
i++
}
return
}
func Solve3() (solution int) {
n := 600851475143
max := int(math.Sqrt(float64(n)))
primes := util.Sieve(max)
for p := range primes {
if n%p == 0 {
n /= p
}
if n == 1 {
return p
}
}
return
}
func Solve10() (solution int) {
for prime := range util.Sieve(2 * 1000 * 1000) {
solution += prime
}
return
}