mirror of
https://github.com/cubixle/codekata-golang.git
synced 2026-04-24 19:54:43 +01:00
47 lines
915 B
Go
47 lines
915 B
Go
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"math/big"
|
|
"strconv"
|
|
)
|
|
|
|
func main() {
|
|
result := 0
|
|
limit, _ := (&big.Int{}).SetString("1000000", 0)
|
|
nLimit := 100
|
|
for i := 1; i <= nLimit; i++ {
|
|
for j := 0; j <= i; j++ {
|
|
bi, _ := (&big.Int{}).SetString(strconv.Itoa(i), 0)
|
|
fi := factorialOf(bi)
|
|
bj, _ := (&big.Int{}).SetString(strconv.Itoa(j), 0)
|
|
fj := factorialOf(bj)
|
|
bk, _ := (&big.Int{}).SetString(strconv.Itoa(i-j), 0)
|
|
fk := factorialOf(bk)
|
|
mik := fj.Mul(fj, fk)
|
|
dvk := mik.Div(fi, mik)
|
|
if x := dvk.Add(dvk, limit.Neg(limit)); x.Int64() >= 0 {
|
|
result++
|
|
}
|
|
}
|
|
}
|
|
fmt.Println(result)
|
|
}
|
|
|
|
func factorialOf(n *big.Int) *big.Int {
|
|
one, _ := (&big.Int{}).SetString("1", 0)
|
|
if n.Int64() <= 2 {
|
|
return one
|
|
}
|
|
p, _ := (&big.Int{}).SetString("1", 0)
|
|
i, _ := (&big.Int{}).SetString("2", 0)
|
|
for {
|
|
p = p.Mul(p, i)
|
|
if i.String() == n.String() {
|
|
break
|
|
}
|
|
i = i.Add(i, one)
|
|
}
|
|
return p
|
|
}
|