88w.go

package main

import (
	"bufio"
	"bytes"
	"fmt"
	"os"
	"runtime/pprof"
	"strconv"
	"sync"
)

func main() {
	profFile, err := os.Create("cpu.prof")
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	defer profFile.Close()
	pprof.StartCPUProfile(profFile)
	defer pprof.StopCPUProfile()

	outFile, err := os.Create("out.go")
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	defer outFile.Close()

	w := bufio.NewWriter(outFile)

	w.WriteString(`package main

import (
	"fmt"
	"bufio"
	"os"
	"strconv"
)

func main() {
	fmt.Print("输入一个五位正整数: ")
	input := bufio.NewScanner(os.Stdin)
	input.Scan()
	d, err := strconv.Atoi(input.Text())
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	if d >= 100000 || d <= 0{
		fmt.Println("数字不符合要求")
		os.Exit(1)
	}
	switch d {
`)

	for i := 1; i <= 99999; i++ {
		fmt.Fprintf(w, "\t\tcase %d: {\n", i)
		w.WriteString(caseN(i))
		w.WriteString("\t\t}\n")
	}

	w.WriteString("\t}\n}")
	w.Flush()
}

var p = [5]string{"个", "十", "百", "千", "万"}

var pool = &sync.Pool{
	New: func() interface{} {
		return new(bytes.Buffer)
	},
}

func caseN(d int) string {
	dd := d
	buffer := pool.Get().(*bytes.Buffer)
	defer func() {
		buffer.Reset()
		pool.Put(buffer)
	}()
	ds := strconv.Itoa(d)
	size := len(ds)
	fmt.Fprintf(buffer, "\t\t\tfmt.Println(\"是个%d位数\")\n", size)
	pp := p[:size]  // BCE
	for i := 0; i < size; i++ {
		fmt.Fprintf(buffer, "\t\t\tfmt.Println(\"%s位数是: %d\")\n", pp[i], d%10)
		d /= 10
	}
	fmt.Fprintf(buffer, "\t\t\tfmt.Println(\"倒过来是: %d\")\n", reverse(dd))
	return buffer.String()
}

func reverse(d int) int {
	res := 0
	for d != 0 {
		res = res*10 + d%10
		d /= 10
	}
	return res
}