java - 如何找到 (x :g)?) 的基数 10

Question

我的作业快结束了，对这个算法的正确方法有点困惑。我需要找到一个数字的 base10:用户提供的基数。

基本上我的程序所做的是接受用户输入，例如 407:8 或 1220:5 等。

我想输出的是这样的。

 INPUT:    407:8 
OUTPUT:    407 base 8 is 263 base 10

我一直在考虑这种漫长的方法，但我确信有一种更简单的方法可以解决这个问题。

附件是我目前所拥有的。感谢观看!!

import javax.swing.JOptionPane;  //gui stuff
import java.util.Scanner;  // Needed for accepting input
import java.text.*;         //imports methods for text handling
import java.lang.Math.*;    //needed for math stuff*

 public class ProjectOneAndreD      //my class + program name
 {


public static void main(String[] args)  //my main
{
    String input1;      //holds user input
    int val=0, rad=0, check1=0;   //holds integer values user gives
   and check  for : handler
    double answer1=0;   //holds the answer!


        Scanner keyboard = new Scanner(System.in);  
  //creates new scanner class

        do      //will continue to loop if no : inputted
        {
           System.out.println("\t****************************************************");
        System.out.println("\t             Loading Project 1. Enjoy!              ");       //title
        System.out.println("\t****************************************************\n\n");

        input1 = JOptionPane.showInputDialog("INPUT: ","EXAMPLE:  160:2");  //prompts user with msgbox w/ example
        System.out.println("Program Running...");       //gives user a secondary notice that everything is ok..

        check1=input1.indexOf(":");     //checks input1 for the :

            if(check1==-1)              //if no : do this stuff
            {
                System.out.println("I think you forgot the ':'.");      //let user know they forgot
                JOptionPane.showMessageDialog(null, "You forgot the ':'!!!");   //another alert to user
            }
                else        //otherwise is they remembered :
                {
                    String numbers [] = input1.split(":"); //splits the string at :

                        val = Integer.parseInt(numbers[0]);   //parses [0] to int and assigns to val
                        rad = Integer.parseInt(numbers[1]);     //parses [1] to int and assigns to rad
                        //answer1 = ((Math.log(val))/(Math.log(rad)));  //mathematically finds first base then
                        //answer1 = Integer.parseInt(val, rad, 10);

                        JOptionPane.showMessageDialog(null, val+" base "+rad+" = BLAH base 10.");  //gives user the results
                        System.out.println("Program Terminated...");            //alerts user of program ending
                }

        }while(check1==-1);     //if user forgot : loop 

    }
}

Answer 1

您可以使用 Integer.parseInt(s, radix)。

answer = Integer.parseInt(numbers[0], rad);

您解析给定基数中的数字。