func main() {
pqrs := make([]int64, 12650) // Products of 4 distinct primes
pos := 0
for i := range iterutil.Subsets(25, 4) {
pqrs[pos] = primes[i[0]] * primes[i[1]] * primes[i[2]] * primes[i[3]]
pos++
}
sliceutil.SortInt64(pqrs)
t0 := float64(time.Now().UnixNano()) / 1000000.0
// Loop trough all numbers
var maxNum int64 = 10000000
var intervalSize int64 = 10000 // Must divide 10^6
var numIntervals int64 = maxNum / intervalSize
isPqrst := make([]bool, intervalSize)
var intervalStart int64 = 0
var intervalEnd int64 = intervalSize
var numPqrst int64 = 0
for i := int64(0); i < numIntervals; i++ {
// Clear sieve for this range
for j := int64(0); j < intervalSize; j++ {
isPqrst[j] = false
}
// Fill sieve with multiples of pqrs
for j := 0; j < len(pqrs); j++ {
t0 := intervalStart / pqrs[j]
t1 := intervalEnd/pqrs[j] + 1
if t0 == 0 {
t0 = 1
}
for t := t0; t < t1; t++ {
pqrst := pqrs[j] * t
if intervalStart <= pqrst && pqrst < intervalEnd {
isPqrst[pqrst-intervalStart] = true
}
}
}
// Sum up the results for this interval
for j := int64(0); j < intervalSize; j++ {
if isPqrst[j] {
numPqrst++
}
}
intervalStart += intervalSize
intervalEnd += intervalSize
}
t1 := float64(time.Now().UnixNano()) / 1000000.0
fmt.Printf("time = %vms\n", t1-t0)
fmt.Printf("N = %v\n", numPqrst)
}
func main() {
p := []int64{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53,
59, 61, 67, 71, 73, 79, 83, 89, 97}
P := make([]int64, 12650)
pqrs := make([][]int64, 12650)
pos := 0
for i := range iterutil.Subsets(25, 4) {
P[pos] = p[i[0]] * p[i[1]] * p[i[2]] * p[i[3]]
pqrs[pos] = make([]int64, 4)
for j := 0; j < 4; j++ {
pqrs[pos][j] = p[i[j]]
}
pos++
}
N := int64(1000)
num := int64(0)
for i := 0; i < len(P); i++ {
fmt.Printf("%v%%\n", float32(i)/12650.0*100.0)
num += (N - 1) / P[i]
uniqueFactors := []int64{}
//LCMoverflow := false
for j := 0; j < i; j++ {
fmt.Printf("j=%v\n", j)
uniqueFactors := sliceutil.Union(uniqueFactors, pqrs[j])
fmt.Printf("%v\n", uniqueFactors)
LCM := sliceutil.ProductInt64(uniqueFactors)
if num < 0 {
panic("num wtf")
}
if LCM > 100000000000000000 || LCM < 0 {
panic("LCM overflow")
}
num = num - ((N - 1) / LCM)
}
}
fmt.Printf("habeeb it %v, %v\n", N, num)
}