/*
package main

import "fmt"

func main() {
	fmt.Println("Hello Eded.Wong")
}
*/

/*
package main

import (
	"fmt"
	"math/rand"
)

func main() {
	fmt.Println("My favorite number is", rand.Intn(10))
}
*/

/*
package main

import (
	"fmt"
	"math"
)

func main() {
	fmt.Printf("Now you have %g problems.", math.Nextafter(2, 3))
}
*/

/*
package main

import (
	"fmt"
	"math"
)

func main() {
	fmt.Println(math.Pi)
}
*/

/*
package main

import "fmt"

func add(x int, y int) int {
	return x + y
}

func main() {
	fmt.Println(add(42, 13))
}
*/

/*
package main

import "fmt"

func add(x, y int) int {
	return x + y
}

func main() {
	fmt.Println(add(42, 13))
}
*/

/*
package main

import "fmt"

func swap(x, y string) (string, string) {
	return y, x
}

func main() {
	a, b := swap("hello", "world")
	fmt.Println(a, b)
}
*/

/*
package main

import "fmt"

func split(sum int) (x, y int) {
	x = sum * 4 / 9
	y = sum - x
	return
}

func main() {
	fmt.Println(split(17))
}
*/

/*
package main

import "fmt"

var c, python, java bool

func main() {
	var i int
	fmt.Println(i, c, python, java)
}
*/

/*
package main

import "fmt"

var i, j int = 1, 2

func main() {
	var c, python, java = true, false, "no!"
	fmt.Println(i, j, c, python, java)
}
*/

/*
package main

import "fmt"

func main() {
	var i, j int = 1, 2
	k := 3
	c, python, java := true, false, "no!"

	fmt.Println(i, j, k, c, python, java)
}
*/

/*
package main

import (
	"fmt"
	"math/cmplx"
)

var (
	ToBe   bool       = false
	MaxInt uint64     = 1<<64 - 1
	z      complex128 = cmplx.Sqrt(-5 + 12i)
)

func main() {
	const f = "%T(%v)\n"
	fmt.Printf(f, ToBe, ToBe)
	fmt.Printf(f, MaxInt, MaxInt)
	fmt.Printf(f, z, z)
}
*/

/*
package main

import "fmt"

func main() {
	var i int
	var f float64
	var b bool
	var s string
	fmt.Printf("%v %v %v %q\n", i, f, b, s)
}
*/

/*
package main

import (
	"fmt"
	"math"
)

func main() {
	var x, y int = 3, 4
	var f float64 = math.Sqrt(float64(x*x + y*y))
	var z int = int(f)
	fmt.Println(x, y, z)
}
*/

/*
package main

import "fmt"

func main() {
	v := 42
	fmt.Printf("v is of type %T\n", v)
}
*/

/*
package main

import "fmt"

const Pi = 3.14

func main() {
	const World = "世界"
	fmt.Println("Hello", World)
	fmt.Println("Happy", Pi, "Day")

	const Truth = true
	fmt.Println("Go rules?", Truth)
}
*/

/*
package main

import "fmt"

const (
	Big   = 1 << 100
	Small = Big >> 99
)

func needInt(x int) int { return x*10 + 1 }
func needFloat(x float64) float64 {
	return x * 0.1
}

func main() {
	fmt.Println(needInt(Small))
	fmt.Println(needFloat(Small))
	fmt.Println(needFloat(Big))
}
*/

/*
package main

import "fmt"

func main() {
	sum := 0
	for i := 0; i < 10; i++ {
		sum += i
	}
	fmt.Println(sum)
}
*/

/*
package main

import "fmt"

func main() {
	sum := 1
	for sum < 1000 {
		sum += sum
	}
	fmt.Println(sum)
}
*/

/*
package main

import (
	"fmt"
	"math"
)

func sqrt(x float64) string {
	if x < 0 {
		return sqrt(-x) + "i"
	}
	return fmt.Sprint(math.Sqrt(x))
}

func main() {
	fmt.Println(sqrt(2), sqrt(-4))
}
*/

/*
package main

import (
	"fmt"
	"math"
)

func pow(x, n, lim float64) float64 {
	if v := math.Pow(x, n); v < lim {
		return v
	}
	return lim
}

func main() {
	fmt.Println(
		pow(3, 2, 10),
		pow(3, 3, 20),
	)
}
*/

/*
package main

import (
	"fmt"
	"math"
)

func Sqrt(x float64) float64 {
	// 起始数
	z := float64(5)

	// 起始数猜测，长度猜想
	xLen := float64(len(string(int(x))))
	if int(xLen)%2 > 0 {
		xLen++
	}

	xLen = xLen * 0.5

	// 起始数位数确认.
	z *= math.Pow(10, xLen)

	for i := 0; i < 10; i++ {
		z = (z + x/z) * 0.5
	}

	return z
}

var arr = []float64{10, 16, 345, 668, 2992, 993, 443, 80, 726642, 469228, 1391791}

func main() {
	fmt.Println(Sqrt(668))
	fmt.Println(math.Sqrt(668))

	for i := 0; i < len(arr); i++ {
		fmt.Println(
			"Number",
			arr[i],
			"Sqrt:",
			Sqrt(arr[i]),
			"mathSqrt:",
			math.Sqrt(arr[i]),
		)
	}
}
*/

/*
package main

import (
	"fmt"
	"runtime"
)

func main() {
	fmt.Print("Go 运行在 ")
	switch os := runtime.GOOS; os {
	case "darwin":
		fmt.Println("OS X.")
	case "linux":
		fmt.Println("Linux.")
	default:
		fmt.Printf("%s.", os)
	}
}
*/

/*
package main

import (
	"fmt"
	"time"
)

func main() {
	fmt.Println("什么时候才星期六?")
	today := time.Now().Weekday()
	switch time.Saturday {
	case today + 0:
		fmt.Println("今天.")
	case today + 1:
		fmt.Println("明天.")
	case today + 2:
		fmt.Println("后天.")
	default:
		fmt.Println("还远着呢！")
	}
}
*/

/*
package main

import (
	"fmt"
	"time"
)

func main() {
	t := time.Now()
	switch {
	case t.Hour() < 12:
		fmt.Println("早上好！")
	case t.Hour() < 17:
		fmt.Println("下午好！")
	default:
		fmt.Println("晚上好！")
	}
}
*/

/*
package main

import "fmt"

func main() {
	defer fmt.Println("world")
	fmt.Println("hello")
}
*/

package main

import "fmt"

func main() {
	fmt.Println("counting")
	for i := 0; i < 10; i++ {
		defer fmt.Println(i)
	}
	fmt.Println("done")
}