复利计算器2.0

 import java.util.Scanner;

  public class fuli {

      /**
       * @param args
       */
     public static void main(String[] args) {
         // TODO Auto-generated method stub
         Scanner caculate = new Scanner(System.in);
         int a = 0;
         while (a == 0 || a == 1 || a == 2 || a == 3) {
             System.out.println("请选择1/2/3：\n1.复利计算终值2.复利计算本金3.单利计算本息");
             int a1 = caculate.nextInt();
             if (a1 == 1) {
                 fuli.CFutureValue();
                 break;
             } else if (a1 == 2) {
                 fuli.CPresentValue();
                 break;
             }

             else if (a1 == 3) {
                 fuli.PrincipalAndInterest();
                 break;
             } else {
                 System.out.println("\n您的输入错误");
                 a1 = a;
             }
         }
     }

     // 复利计算终值
     static void CFutureValue() {
         Scanner fuli = new Scanner(System.in);
         System.out.println("请输入本金：");
         double PresentValue = fuli.nextDouble(); // 本金
         System.out.println("请输入存款年数：");
         int year = fuli.nextInt(); // 存钱年数
         System.out.println("请输入利率：");
         double r = fuli.nextDouble(); // 利率
        double sum = 1;
         for (int i = 1; i <= year; i++) {
             sum = (1 + r) * sum;
         }
         System.out.println("总额为：" + sum * PresentValue);
     }

     // 复利计算本金
     static void CPresentValue() {

         Scanner fuli = new Scanner(System.in);
         System.out.println("请输入终值：");
         double sum = fuli.nextDouble(); // 终值
         System.out.println("请输入存款年数：");
          int year = fuli.nextInt(); // 存钱年数
          System.out.println("请输入利率：");
          double r = fuli.nextDouble(); // 利率
          double PresentValue = 1;
          for (int i = 1; i <= year; i++) {
              PresentValue = (1 + r) * PresentValue;
          }
          System.out.println("总额为：" + sum * (1 / PresentValue));
      }

      // 单利计算本息
      static void PrincipalAndInterest() {
          Scanner danli = new Scanner(System.in);
         System.out.println("请输入本金：");
          double PresentValue = danli.nextDouble(); // 本金
          System.out.println("请输入存款年数：");
          int Annuity = danli.nextInt(); // 存钱年数
          System.out.println("请输入利率：");
          double r = danli.nextDouble(); // 利率
          double sum1 = 1;
          sum1 = (1 + r * Annuity) * PresentValue;
          System.out.println("本息为：" + sum1);
      }