Golang implements BigInteger large number calculation

Golang Medium big.Int The library supports large number calculation , Based on this library, a layer of Bitinteger, Support large numbers of string types , Add, subtract, multiply, divide, etc . Other calculations can refer to the calculation based on big.Int To achieve .

package BigIntege



import (

    "fmt"

    "math/big"

)



const DecBase = 10



// BigInteger wrapper for big.Int

type BigInteger struct {

    Value *big.Int

}



func NewBigInteger(value string) \*BigInteger {

    var val big.Int

    newVal, ok := val.SetString(value, DecBase)

    if ok {

        return &BigInteger{

            Value: newVal,

        }

    }

    return NewZeroBigInteger()

}



func NewZeroBigInteger() *BigInteger {

    return &BigInteger{

        Value: big.NewInt(0),

    }

}



func (x *BigInteger) Add(y *BigInteger) {

    x.Value = x.Value.Add(x.Value, y.Value)

}



func (x *BigInteger) Sub(y *BigInteger) {

    x.Value = x.Value.Sub(x.Value, y.Value)

}



// Cmp compares x and y and returns:

//

//   -1 if x <  y

//    0 if x == y

//   +1 if x >  y

func (x *BigInteger) Cmp(y *BigInteger) int {

    return x.Value.Cmp(y.Value)

}



func (x *BigInteger) String() string {

    return x.Value.String()

}



// Sum  Add 

func Sum(x, y *BigInteger) *BigInteger {

    z := NewZeroBigInteger()

    z.Add(x)

    z.Add(y)

    return z

}



// Sub  Subtraction 

func Sub(x, y *BigInteger) *BigInteger {

    z := NewBigInteger(x.String())

    z.Sub(y)

    return z

}



// Mul  punishment 

func Mul(x, y \*BigInteger) \*BigInteger {

    t := NewZeroBigInteger()

    z := t.Value.Mul(x.Value, y.Value)

    return &BigInteger{Value: z}

}



// Div  division 

func Div(x, y *BigInteger) *BigInteger {

    t := NewZeroBigInteger()

    z := t.Value.Div(x.Value, y.Value)

    return &BigInteger{Value: z}

}



func isValidBigInt(val string) error {

    _, ok := big.NewInt(0).SetString(val, 10)

    if !ok {

        return fmt.Errorf("parse string to big.Int failed, actual: %s", val)

    }

    return nil

}

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