软件工程个人作业—四则运算2

1、程序设计思想：

      1）首先定义生成的计算式的总数，确定计算的不同方式，选择计算的数值范围；

      2）定义不同的类，编写对应的代码进行整数运算、真分数运算（分数的约分化简）、乘法运算、括号运算、有负数的加减法运算、有余数的除法运算；

      3）判断所生成的计算式中是否存在重复的题目，如果存在则返回false，不然返回true；

2、程序源代码：

package demo;

import java.util.Random;
import java.util.Scanner;

public class lianxi2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int N,M;
        Scanner scan = new Scanner(System.in);
        System.out.print("请输入总数：");
        N = scan.nextInt();
        String[] jss = new String[N];
        System.out.println("1、整数计算式，2、真分数计算式，3、乘除法运算，4、括号运算（最多可以支持十个数参与运算），5、有负数的加减运算，6、有余数的除法运算");
        System.out.print("请选择运算的方式:");
        int p = scan.nextInt();
        if(p == 1) {
            jss = createZhengShuJiSuanShi(N);
        }
        else if(p==2){
            jss = createZhenFenShuJiSuanShi(N);
        }
        else if(p==3){
            jss = createChengChuFaYunSuan(N);
        }
    /*else if(p==4){
            jss = createKuoHaoYunSuan(N);
        } */
        else if(p==5){
            jss = createFuShuYunSuan(N);
        }
        else if(p==6){
            jss=createYuShuYunSuan(N);
        } 
        scan.close();
        
        //显示结果
        for(int i = 0;i < N;i++) {
            System.out.println((i + 1) + " : " + jss[i]);
        }
    }
    
    //生成真分数计算式
    public static String[] createZhenFenShuJiSuanShi(int n) {
        int x,y,z,a,b,i = 0;
        int M;
        Scanner scan=new Scanner(System.in);
        System.out.print("请输入运算的数值范围：");
        M=scan.nextInt();
        String[] jss = new String[n];
        String t = "";
        Random rd = new Random();
        
        while(i < n) {
            a = rd.nextInt(M);
            b = rd.nextInt(M);
            
            if(a != 0 && b != 0){
                x = rd.nextInt(a);
                y = rd.nextInt(b);
                z = rd.nextInt(4);
                t = "";
                if(y != 0){
                    if(z == 0) {
                        if((x * b + y * a) < (a * b))
                            t = "" + yueJian(x, a) + " + " + yueJian(y, b) + "=" + yueJian((x * b + y * a), (a * b));
                    
                    }else if(z == 1) {
                        if((x * b - y * a) >= 0 && (x * b - y * a) < (a * b))
                            t = "" + yueJian(x, a) + " - " + yueJian(y, b) + "=" + yueJian((x * b - y * a), (a * b));
                    
                    }else if(z == 2) {
                        if((x * y) < (a * b))
                            t = "" + yueJian(x, a) + " * " + yueJian(y, b) + "=" + yueJian((x * y),(a * b));
                    
                    }else{
                        if((y / b) != 0){
                            if((x * b) < (a * y))
                                t = "" + yueJian(x, a) + " / " + yueJian(y, b) + "=" + yueJian((x * b),(a * y));
                        }
                    }
                    if((!t.equals("")) && buChong(jss,t,i)){
                        jss[i++] = t;
                    }
                }
            }
        }
        return jss;
    }
    
    //生成整数计算式
    public static String[] createZhengShuJiSuanShi(int n) {
        int x,y,z,i = 0;
        int M;
        Scanner scan=new Scanner(System.in);
        System.out.print("请输入运算的数值范围：");
        M=scan.nextInt();
        String[] jss = new String[n];
        String t = "";
        Random rd = new Random();
        while(i < n) {
            x = rd.nextInt(M);
            y = rd.nextInt(M);
            z = rd.nextInt(4);
            
                if(z == 0) {
                    t = "" + x + " + " + y  + "="+(x+y);
                }else if(z == 1 && x >= y) {
                    t = "" + x + " - " + y  + "=" +(x-y) ;
                }else if(z == 2) {
                    t = "" + x + " * " + y  + "=" + (x*y);
                }else{
                    if(y != 0){
                        if(x % y == 0){
                            t = "" + x + " / " + y  + "=" + (x/y);
                            }
                    }
                }
                
                if(buChong(jss,t,i)){
                    jss[i++] = t;
                }
            
        }
        return jss;
    }
    
    //约简分子分母，如果分子为0则返回0
    public static String yueJian(int a,int b){
        
        int y = 1;
        for(int i = a;i >= 1;i--) {
            if(a % i == 0 && b % i == 0){
                y = i;
                break;
            }
        }
        int z = a / y;
        int m = b / y;
        if(z == 0) {
            return "0";
        }
        return "" + z + "/" + m;
    }
    //乘除法运算
    public static String[] createChengChuFaYunSuan(int n) {
        int x,y,z,i = 0;
        int M;
        Scanner scan=new Scanner(System.in);
        System.out.print("请输入运算的数值范围：");
        M=scan.nextInt();
        String[] jss = new String[n];
        String t = "";
        Random rd = new Random();
        while(i < n) {
            x = rd.nextInt(M);
            y = rd.nextInt(M);
            z = rd.nextInt(2);
            
                if(z == 0) {
                    t = "" + x + " * " + y  + "=" + (x*y);
                }else{
                    if(y != 0){
                        if(x % y == 0){
                            t = "" + x + " / " + y  + "=" + (x / y);
                            }
                    }
                }
                if(buChong(jss,t,i)){
                    jss[i++] = t;
                }
            
        }
        return jss;
    }
    //括号运算
    /*public static String[] createKuoHaoYunSuan(int n) {

    } */
    //负数运算
    public static String[] createFuShuYunSuan(int n) {
        int x,y,z,i = 0;
        int M;
        Scanner scan=new Scanner(System.in);
        System.out.print("请输入运算的数值范围：");
        M=scan.nextInt();
        String[] jss = new String[n];
        String t = "";
        Random rd = new Random();
        while(i < n) {
            x = -rd.nextInt(M);
            y = -rd.nextInt(M);
            z = rd.nextInt(1);
            if(z == 0) {
                t = "(" + x +")"+ " + " +"("+ y+")"+"=" + (x + y);
                
            }else{
                t = "(" + x+")" + " - " +"("+ y+")"  + "=" + (x - y);
        }
            if(buChong(jss,t,i)){
                jss[i++] = t;
            }
    }
        return jss;
}
    //余数运算
    public static String[] createYuShuYunSuan(int n) {
        int x,y,z,i = 0;
        int M;
        Scanner scan=new Scanner(System.in);
        System.out.print("请输入运算的数值范围：");
        M=scan.nextInt();
        String[] jss = new String[n];
        String t = "";
        Random rd = new Random();
        while(i < n) {
            x = rd.nextInt(M);
            y = rd.nextInt(M);
            if(y != 0){
                if(x % y == 0){
                    t = "" + x + " / " + y  + "=" + (x / y);}
                else{
                    int a,b;
                    a=x%y;
                    b=(x-a)/y;
                    t=""+x+"/"+y+"="+b+"……"+a;
                }
            }
            if(buChong(jss,t,i)){
                jss[i++] = t;
            }
        }
        return jss;
    }  
    //检测是否重复（检测j是否与jss数组的前n个重复）重复返回FALSE 不重复返回TRUE
    public static boolean buChong(String[] jss,String j,int n) {
        for(int i = 0;i < n;i++) {
            if(jss[i].equals(j)){
                return false;
            }
        }
        return true;
    }
}

3、运行结果截图：

4、总结：

      在这次的实验中，也更加熟悉了程序的编码设计，对于程序进行了不少的完善，不过略有遗憾的是没有实现四则运算的括号运算，不清楚怎样产生随机的括号，之后自己会去学习，然后对于程序进行进一步的完善。