问题;

对分数进行四则运算，使结果仍然是分数

代码：

Test.java

public class Test {

public static void main(String[]args){

Rational r1=new Rational();

Rational r2=new Rational();//声明两个分数对象

r1.setNumAndDen(3,5);

int r1fenzi=r1.getNum();

int r1fenmu=r1.getDen();//输入第一个分数并化简

r2.setNumAndDen(3,2);

int r2fenzi=r2.getNum();

int r2fenmu=r2.getDen();//输入第一个分数并化简

Rational result=r1.add(r2);

int resultFenzi=result.getNum();

int resultFenmu=result.getDen();//得到结果

System.out.printf("\n%d/%d+%d/%d=%d/%d",r1fenzi,r1fenmu,r2fenzi,r2fenmu,resultFenzi,resultFenmu);

result=r1.sub(r2);//减法

resultFenzi=result.getNum();

resultFenmu=result.getDen();//得到结果

System.out.printf("\n%d/%d-%d/%d=%d/%d",r1fenzi,r1fenmu,r2fenzi,r2fenmu,resultFenzi,resultFenmu);

result=r1.muti(r2);//乘法

resultFenzi=result.getNum();

resultFenmu=result.getDen();//得到结果

System.out.printf("\n%d/%d*%d/%d=%d/%d",r1fenzi,r1fenmu,r2fenzi,r2fenmu,resultFenzi,resultFenmu);

result=r1.div(r2);//除法

resultFenzi=result.getNum();

resultFenmu=result.getDen();//得到结果

System.out.printf("\n%d/%d/%d/%d=%d/%d",r1fenzi,r1fenmu,r2fenzi,r2fenmu,resultFenzi,resultFenmu);

}

}

Rational.java

public class Rational {

int num;

int den;

void setNumAndDen(int fenzi,int fenmu){

int m=1,n=1;

if(fenzi<0)

m=-1*fenzi;

if(fenmu<0)

n=-1*fenmu;

if(fenzi==0){

num=0;

den=1;

return ;

}

int c=f(m,n);//把输入的分数进行约分

num=fenzi/c;

den=fenmu/c;

if(num<0&&den<0){

num=-num;

den=-den;//如果分子和分母都是负的，那就转换为正的

}

}

int getNum(){

return num;

}

int getDen(){

return den;

}

int f(int a,int b){

if(a

int c=a;

a=b;

b=c;

}//转换使运算的时候a是最大的再进行求最大公约数

int r=a%b;

while(r!=0){

a=b;

b=r;

r=a%b;

}

return b;

}

Rational add(Rational r){//加法运算

int a=r.getNum();

int b=r.getDen();//得到分子分母

int newNum=num*b+den*a;//分子等于两数的分子都乘以对方的分母再相加

int newDen=den*b;//分母等于两个分母相乘

Rational result=new Rational();//新的分数

result.setNumAndDen(newNum,newDen);//再进行约分

return result;

}

Rational sub(Rational r){//减法运算

int a=r.getNum();

int b=r.getDen();//得到分子分母

int newNum=num*b-den*a;//分子等于两数的分子都乘以对方的分母再相减

int newDen=den*b;//分母等于两个分母相乘

Rational result=new Rational();//新的分数

result.setNumAndDen(newNum,newDen);//再进行判断约分

return result;

}

Rational muti(Rational r){//乘法运算

int a=r.getNum();

int b=r.getDen();//得到分子分母

int newNum=num*a;//分子等于两数的分子相乘

int newDen=den*b;//分母都与两个分母相乘

Rational result=new Rational();//新的分数

result.setNumAndDen(newNum,newDen);//再进行判断约分

return result;

}

Rational div(Rational r){//除法运算

int a=r.getNum();

int b=r.getDen();//得到分子分母

int newNum=num*b;//

int newDen=den*a;//改为乘以倒数的形式

Rational result=new Rational();//新的分数

result.setNumAndDen(newNum,newDen);//再进行判断约分

return result;

}

}

运行结果：