package main

import "fmt"

func main() {
	var num1, num2 float64
	var operator string

	fmt.Println("请输入第一个数字:")
	fmt.Scanln(&num1)

	fmt.Println("请输入运算符 (+, -, *, /):")
	fmt.Scanln(&operator)

	fmt.Println("请输入第二个数字:")
	fmt.Scanln(&num2)

	result := 0.0

	switch operator {
	case "+":
		result = num1 + num2
	case "-":
		result = num1 - num2
	case "*":
		result = num1 * num2
	case "/":
		if num2 != 0 {
			result = num1 / num2
		} else {
			fmt.Println("错误：除数不能为零！")
			return
		}
	default:
		fmt.Println("错误：无效的运算符！")
		return
	}

	fmt.Printf("结果：%v %v %v = %v\n", num1, operator, num2, result)
}