102 lines
2.3 KiB
Go
102 lines
2.3 KiB
Go
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"math/big"
|
||
|
|
"net/http"
|
||
|
|
"strconv"
|
||
|
|
"time"
|
||
|
|
)
|
||
|
|
|
||
|
|
func calculatePi(n int) *big.Float {
|
||
|
|
precision := uint(n * 14)
|
||
|
|
pi := new(big.Float).SetPrec(precision)
|
||
|
|
pi.SetInt64(0)
|
||
|
|
|
||
|
|
one := new(big.Float).SetInt64(1)
|
||
|
|
two := new(big.Float).SetInt64(2)
|
||
|
|
four := new(big.Float).SetInt64(4)
|
||
|
|
five := new(big.Float).SetInt64(5)
|
||
|
|
six := new(big.Float).SetInt64(6)
|
||
|
|
eight := new(big.Float).SetInt64(8)
|
||
|
|
sixteen := new(big.Float).SetInt64(16)
|
||
|
|
|
||
|
|
for i := 0; i < n; i++ {
|
||
|
|
k := new(big.Float).SetInt64(int64(i))
|
||
|
|
|
||
|
|
// Obliczanie 16^i
|
||
|
|
powSixteen := new(big.Float).SetInt64(1)
|
||
|
|
for j := 0; j < i; j++ {
|
||
|
|
powSixteen.Mul(powSixteen, sixteen)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Obliczanie 1/16^i
|
||
|
|
denominator := new(big.Float).SetPrec(precision)
|
||
|
|
if powSixteen.Sign() != 0 {
|
||
|
|
denominator.Quo(one, powSixteen)
|
||
|
|
} else {
|
||
|
|
continue
|
||
|
|
}
|
||
|
|
|
||
|
|
// Obliczanie poszczególnych składników
|
||
|
|
term1 := new(big.Float).SetPrec(precision)
|
||
|
|
term1.Mul(eight, k)
|
||
|
|
term1.Add(term1, one)
|
||
|
|
term1.Quo(four, term1)
|
||
|
|
|
||
|
|
term2 := new(big.Float).SetPrec(precision)
|
||
|
|
term2.Mul(eight, k)
|
||
|
|
term2.Add(term2, four)
|
||
|
|
term2.Quo(two, term2)
|
||
|
|
|
||
|
|
term3 := new(big.Float).SetPrec(precision)
|
||
|
|
term3.Mul(eight, k)
|
||
|
|
term3.Add(term3, five)
|
||
|
|
term3.Quo(one, term3)
|
||
|
|
|
||
|
|
term4 := new(big.Float).SetPrec(precision)
|
||
|
|
term4.Mul(eight, k)
|
||
|
|
term4.Add(term4, six)
|
||
|
|
term4.Quo(one, term4)
|
||
|
|
|
||
|
|
// Łączenie składników
|
||
|
|
sum := new(big.Float).SetPrec(precision)
|
||
|
|
sum.Sub(term1, term2)
|
||
|
|
sum.Sub(sum, term3)
|
||
|
|
sum.Sub(sum, term4)
|
||
|
|
|
||
|
|
// Mnożenie przez 1/16^i i dodawanie do wyniku
|
||
|
|
sum.Mul(sum, denominator)
|
||
|
|
pi.Add(pi, sum)
|
||
|
|
}
|
||
|
|
|
||
|
|
return pi
|
||
|
|
}
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
http.HandleFunc("/pi", func(w http.ResponseWriter, r *http.Request) {
|
||
|
|
w.Header().Set("Access-Control-Allow-Origin", "*")
|
||
|
|
|
||
|
|
precisionStr := r.URL.Query().Get("precision")
|
||
|
|
precision, err := strconv.Atoi(precisionStr)
|
||
|
|
if err != nil {
|
||
|
|
http.Error(w, "Invalid precision parameter", http.StatusBadRequest)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
start := time.Now()
|
||
|
|
pi := calculatePi(precision)
|
||
|
|
duration := time.Since(start)
|
||
|
|
|
||
|
|
// Format PI to specified precision
|
||
|
|
piFormatted := fmt.Sprintf("%.*f", precision, pi)
|
||
|
|
|
||
|
|
response := fmt.Sprintf(`{"pi": "%s", "time": "%v", "language": "Go"}`, piFormatted, duration)
|
||
|
|
w.Header().Set("Content-Type", "application/json")
|
||
|
|
fmt.Fprint(w, response)
|
||
|
|
})
|
||
|
|
|
||
|
|
fmt.Println("Go server starting on port 8081...")
|
||
|
|
http.ListenAndServe(":8081", nil)
|
||
|
|
}
|