solution to #amazon hiring final4 test2: stack sequence

stackseq.go

package main

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

type Stack struct {
	store     []int
	top, capa int
}

func NewStack(capa int) *Stack {
	s := new(Stack)
	s.store = make([]int, capa)
	s.top = 0
	s.capa = capa
	return s
}

func (id *Stack) push(i int) {
	if id.top == id.capa {
		panic("stack overflow!")
	}
	id.store[id.top] = i
	id.top++
}

func (id *Stack) pop() int {
	if id.top == 0 {
		panic("stack overflow!")
	}
	id.top--
	return id.store[id.top]
}

func (id *Stack) peek() int {
	if id.top == 0 {
		return -1
	}
	return id.store[id.top-1]
}

func (id *Stack) isempty() bool {
	return !(id.top > 0)
}

func convert(s string) ([]int, int) {
	ss := strings.Split(s, " ")
	ret := make([]int, len(ss))
	for i := 0; i < len(ss); i++ {
		ret[i], _ = strconv.Atoi(ss[i])
	}
	return ret, len(ss)
}

func getSeq(input1, input2 string) string {
	origin, len1 := convert(input1)
	result, len2 := convert(input2)
	if len1 != len2 {
		return "None"
	}
	i, j := 1, 0
	mark := make(map[int]int)
	for k := 0; k < len1; k++ {
		mark[origin[k]] = k + 1
	}
	stack := NewStack(len1)
	stack.push(origin[0])
	ret := "push1"
	for i < len1 || !stack.isempty() {
		if !stack.isempty() && stack.peek() == result[j] {
			a := stack.pop()
			j++
			ret += "|pop" + strconv.Itoa(mark[a])
		} else {
			if i == len1 {
				break
			}
			stack.push(origin[i])
			ret += "|push" + strconv.Itoa(mark[origin[i]])
			i++
		}
	}
	if j != len1 {
		return "None"
	}
	return string(ret)
}

func main() {
	stdin := bufio.NewReader(os.Stdin)
	var seq string
	for {
		origin, err := stdin.ReadString('\n')
		if err != nil {
			break
		}
		result, err := stdin.ReadString('\n')
		if err != nil {
			break
		}
		origin = strings.TrimRight(origin, "\n")
		result = strings.TrimRight(result, "\n")
		seq = getSeq(origin, result)
		fmt.Println(seq)
	}
}