算法训练 前缀表达式

Problem:

AcCode:

import java.util.Scanner;

public class Main{
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		char ysf = in.next().charAt(0);
		int numA = in.nextInt();
		int numB = in.nextInt();
		switch (ysf) {
		case '+':
			System.out.println(numA+numB);
			break;
		case '-':
			System.out.println(numA-numB);
			break;
		case '*':
			System.out.println(numA*numB);
			break;
		case '/':
			System.out.println(numA/numB);
			break;
		default:
			break;
		}
	}
}