ZigZagSequence.go

ZigZagSequence.go

package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"sort"
	"strconv"
	"strings"
)

func findZigZagSequence(n int64, list []int64) []int64 {

	mid := (n+1)/2 - 1
	println("MID: ", mid)
	println("N: ", n)

	sort.Slice(list, func(i, j int) bool { return list[i] < list[j] })
	list[mid], list[n-1] = list[n-1], list[mid]

	st := mid + 1
	ed := n - 1 - 1
	println("ST: ", st)
	println("ED: ", ed)
	for i := st; i < ed; i++ {
		list[st], list[ed] = list[ed], list[st]
		st = st + 1
		ed = ed - 1
	}

	return list

}

func main() {
	reader := bufio.NewReaderSize(os.Stdin, 16*1024*1024)

	aTemp, err := strconv.ParseInt(strings.TrimSpace(readLine(reader)), 10, 64)
	checkError(err)
	nTemp, err2 := strconv.ParseInt(strings.TrimSpace(readLine(reader)), 10, 64)
	checkError(err2)
	temp := strings.Split(strings.TrimSpace(readLine(reader)), " ")

	var v []int64

	for i := aTemp - 1; i < nTemp; i++ {
		aItemTemp, err := strconv.ParseInt(temp[i], 10, 64)
		checkError(err)
		aItem := aItemTemp
		v = append(v, aItem)
	}

	result := findZigZagSequence(nTemp, v)
	for i, v := range result {
		if i == len(result)-1 {
			fmt.Printf("%d\n", v)
		} else {
			fmt.Printf("%d ", v)
		}
	}
}

func readLine(reader *bufio.Reader) string {
	str, _, err := reader.ReadLine()
	if err == io.EOF {
		return ""
	}

	return strings.TrimRight(string(str), "\r\n")
}

func checkError(err error) {
	if err != nil {
		panic(err)
	}
}