package main

import (
    "crypto/rand"
    "fmt"
    "math/big"
)

func main() {
    //var i1 int
    //i1 = 9223372036854775807
    //fmt.Printf("%T, %d\n", i1, i1)
    //var i2 int8
    //i2 = 127
    //fmt.Printf("%T, %d\n", i2, i2)
    // 生成大整数
    max := new(big.Int).Lsh(big.NewInt(1), 128)
    fmt.Println(max)
    // 生成大整数随机数
    serialNumber, _ := rand.Int(rand.Reader, max)
    fmt.Println(serialNumber)
}