题解 | #设计getMin功能的栈#

package main

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

func main() {
	var N int
	fmt.Scanln(&N)

	//初始化栈结构
	gsm := initStack()
	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < N; i++ {
		sc.Scan()
		curline := strings.Split(sc.Text(), " ")
		operation := curline[0]
		switch operation {
		case "push":
			n, _ := strconv.Atoi(curline[1])
			gsm.push(n)
		case "pop":
			fmt.Println(gsm.pop())
		case "getMin":
			fmt.Println(gsm.getMin())
		}

	}

}

type getMinStack struct {
	numStack []int //记录数据的栈
	minStack []int //记录最小值的栈
}

//初始化
func initStack() getMinStack {
	return getMinStack{[]int{}, []int{}}
}

func (this *getMinStack) push(n int) {
	l := len(this.numStack)
	this.numStack = append(this.numStack, n)
	if l == 0 {
		this.minStack = append(this.minStack, n)
		return
	}
	curMin := this.minStack[l-1]
	if curMin > n {
		this.minStack = append(this.minStack, n)
	} else {
		this.minStack = append(this.minStack, curMin)
	}
}

func (this *getMinStack) pop() int {
	l := len(this.numStack)
	n := this.numStack[l-1]
	this.numStack = this.numStack[0 : l-1]
	this.minStack = this.minStack[0 : l-1]
	return n
}
func (this *getMinStack) getMin() int {
	return this.minStack[len(this.minStack)-1]
}