四则运算3

又重新整理了一下代码，想的比较简单，没有真正的实现真分数，往后再继续改进

package NM;
import java.util.*;
public class SurF {
      public static void main (String[] agrs){
          Scanner sc=new Scanner(System.in);
          Random r=new Random();
          int op= 0;
          int n = 0;
          double a,b,c,d;
          String[] s={"+","-","*","/"};
              while(true){
               System.out.println("选择功能：\n0.退出1.简单的加减乘除运算 2.含分数运算");
               op= sc.nextInt();
               if (0 == op) {break;}
               if (1 == op) {
                   int count1=0,count2=0;
                      System.out.println("请输入题目个数(5分/题):");
                      int num=sc.nextInt();
                      System.out.println("请输入算数范围:");
                      int min=sc.nextInt();
                      int max=sc.nextInt();
                      String[] ask=new String[num];
                      for(int i=0;i<num;i++){
                          a=(int)(Math.random()*(max-min)+min);
                          int l= r.nextInt(s.length);//随机数，小于数组的长度数, 0~3
                          b=(int)(Math.random()*(max-min+1)+min);
                          ask[i]=String.valueOf(a+s[l]+b+"=");
                          System.out.print(ask[i]);
                          System.out.print("");
                          int answer=sc.nextInt();
                          if("+"==s[l]){
                                  if(answer==a+b){
                                            System.out.println("this is right!");                              
                                        count1++;
                                        }
                                        else {
                                           System.out.println("this is wroing!"+"正确答案是:"+(a+b));
                                           count2++;
                                           }
                          }
                          else if("-"==s[l]){
                                 if((a-b)>-11){
                                        if(answer==a-b){
                                            System.out.println("this is right!");
                                            count1++;
                                        }
                                        else {
                                           System.out.println("this is wroing!"+"正确答案是:"+(a-b));
                                           count2++;
                                           }
                                 }
                                 else{
                                      a=(int)(Math.random()*(max-min)+min);; 
                                      b=(int)(Math.random()*(max-min)+min);;
                                      if(answer==a-b){
                                            System.out.println("this is right!");
                                            count1++;
                                        }
                                        else {
                                           System.out.println("this is wroing!"+"正确答案是:"+(a-b));
                                           count2++;
                                           }   
                                 }
                                }
                             else if("*"==s[l]){
                              if(answer==a*b){
                                     System.out.println("this is right!");
                                     count1++;
                                 }
                              else {
                                     System.out.println("this is wroing!"+"正确答案是:"+(a*b));
                                     count2++;
                                 }
                             }
                             else if("/"==s[l]){
                                     if(answer==a/b){
                                            System.out.println("this is right!");
                                            count1++;
                                        }
                                     else {
                                          System.out.println("this is wroing!"+"正确答案是:"+String.format("%.2f",a/b));
                                          count2++;
                                        }
                             } 
                          }
                      System.out.println("此题对了:"+count1+" "+"错了:"+count2+" "+"得分为:"+5*count1);
                    }
               else if (2 == op) {
                   int count1=0,count2=0;
                   double CountAnswer1,CountAnswer2,CountAnswer;
                      System.out.println("请输入题目个数(5分/题):");
                      int num=sc.nextInt();
                      System.out.println("请输入算数范围:");
                      int min=sc.nextInt();
                      int max=sc.nextInt();
                      String[] ask=new String[num];
                      for(int i=0;i<num;i++){
                          a=(int)(Math.random()*(max-min)+min);
                          b=(int)(Math.random()*(max-min)+min);
                          c=(int)(Math.random()*(max-min)+min);
                          d=(int)(Math.random()*(max-min)+min);
                          int l= r.nextInt(s.length);//随机数，小于数组的长度数, 0~3
                          ask[i]=String.valueOf("("+a+"/"+b+")"+s[l]+"("+c+"/"+d+")"+"=");
                          System.out.print(ask[i]);
                          System.out.print("");
                          double answer=sc.nextDouble();
                          if("+"==s[l]){
                              CountAnswer1=(int)a/b;
                              CountAnswer2=(int)c/d;
                              CountAnswer=(double)CountAnswer1+CountAnswer2;
                              if(CountAnswer==answer){
                                            System.out.println("this is right!");
                                            count1++;
                                        }
                                    else {
                                           System.out.println("this is wroing!"+"正确答案是:"+String.format("%.2f",CountAnswer));
                                           count2++;
                                           }
                          }
                          if("-"==s[l]){
                              CountAnswer1=(int)a/b;
                              CountAnswer2=(int)c/d;
                              CountAnswer=(double)CountAnswer1-CountAnswer2;
                              if(CountAnswer==answer){
                                            System.out.println("this is right!");
                                            count1++;
                                        }
                                    else {
                                           System.out.println("this is wroing!"+"正确答案是:"+String.format("%.2f",CountAnswer));
                                           count2++;
                                           }
                          }
                          if("*"==s[l]){
                              CountAnswer1=(int)a/b;
                              CountAnswer2=(int)c/d;
                              CountAnswer=(double)CountAnswer1*CountAnswer2;
                              if(CountAnswer==answer){
                                            System.out.println("this is right!");
                                            count1++;
                                        }
                                    else {
                                           System.out.println("this is wroing!"+"正确答案是:"+String.format("%.2f",CountAnswer));
                                           count2++;
                                           }
                          }
                          if("/"==s[l]){
                              CountAnswer1=(int)a/b;
                              CountAnswer2=(int)c/d;
                              CountAnswer=(double)CountAnswer1/CountAnswer2;
                              if(CountAnswer==answer){
                                            System.out.println("this is right!");
                                            count1++;
                                        }
                                    else {
                                           System.out.println("this is wroing!"+"正确答案是:"+String.format("%.2f",CountAnswer));
                                           count2++;
                                           }
                          }
                      }
                      System.out.println("此题对了:"+count1+" "+"错了:"+count2+" "+"得分为:"+5*count1);
               }
                
               else{
                   System.out.println("输入有误，请重新输入；");
               }
              }
              
      }
}