1 public class Rational {
2
3 private int numerator;
4 private int denominator;
5
6 public Rational(int aNumerator, int aDenominator){
7 int r = gcd(aDenominator, aNumerator);
8 numerator = aNumerator / r;
9 denominator = aDenominator / r;
10 sign();
11 }
12
13 private static int gcd(int a, int b){
14 if(b == 0){
15 return a;
16 }
17 else{
18 return gcd(b, a % b);
19 }
20 }
21
22 private void sign(){
23 if(denominator < 0){
24 numerator = -numerator;
25 denominator = -denominator;
26 }
27 }
28
29 public Rational plus(Rational b){
30 int d = this.denominator * b.denominator;
31 int n = this.numerator * b.denominator + b.numerator * this.denominator;
32 return new Rational(n, d);
33 }
34
35 public Rational minus(Rational b){
36 int d = this.denominator * b.denominator;
37 int n = this.numerator * b.denominator - b.numerator * this.denominator;
38 return new Rational(n, d);
39 }
40
41 public Rational times(Rational b){
42 int d = this.denominator * b.denominator;
43 int n = this.numerator * b.numerator;
44 return new Rational(n, d);
45 }
46
47 public Rational divides(Rational b){
48 return times(new Rational(b.denominator, b.numerator));
49 }
50
51 public boolean equals(Object b){
52 if(this == b)return true;
53 if(b == null)return false;
54 if(this.getClass() != b.getClass())return false;
55
56 Rational that = (Rational)b;
57 if(this.numerator == that.numerator && this.denominator == that.denominator)return true;
58 return false;
59 }
60
61 public String toString(){
62 return this.numerator + "/" + this.denominator;
63 }
64
65 public static void main(String[] args) {
66 Rational a = new Rational(8, 30);
67 Rational b = new Rational(32, 40);
68 System.out.println("a = " + a);
69 System.out.println("b = " + b);
70 System.out.println("a + b = " + a.plus(b));
71 System.out.println("a - b = " + a.minus(b));
72 System.out.println("b - a = " + b.minus(a));
73 System.out.println("a * b = " + a.times(b));
74 System.out.println("a / b = " + a.divides(b));
75 System.out.println("b / a = " + b.divides(a));
76 System.out.println("a == b? " + (a.equals(b) == true? "true":"false"));
77 }
78
79 }
