matin mortazavi

src/main/java/Rational/Rational.java

@@ -55,26 +55,42 @@ public class Rational {
     // Formula: a/b - c/d = (a*d - c*b) / (b*d)
     public Rational subtract(Rational other) {
         // YOUR CODE HERE
-        return null; // Remove this line when implemented
+        int NewNumerator = ((this.numerator)*other.denominator)-((this.denominator)*other.numerator) ;
+        int NewDenominator = (this.denominator)*other.denominator;
+
+        return new Rational(NewNumerator ,NewDenominator);
+
+
+        // Remove this line when implemented
     }
 
     // TODO: Static method - r1 - r2
     public static Rational subtract(Rational r1, Rational r2) {
         // YOUR CODE HERE
-        return null; // Remove this line when implemented
+        int NewNumerator = (r1.numerator* r2.denominator)-(r1.denominator* r2.numerator) ;
+        int NewDenominator = r1.denominator* r2.denominator ;
+
+        return new Rational(NewNumerator ,NewDenominator);
     }
 
     // TODO: Instance method - this * other
     // Formula: (a/b) * (c/d) = (a*c) / (b*d)
     public Rational multiply(Rational other) {
         // YOUR CODE HERE
-        return null; // Remove this line when implemented
+        int NewNumerator = this.numerator*other.numerator ;
+        int NewDenominator = this.denominator*other.denominator ;
+
+        return new Rational(NewNumerator ,NewDenominator);
     }
 
     // TODO: Static method - r1 * r2
     public static Rational multiply(Rational r1, Rational r2) {
+        int NewNumerator = r1.numerator* r2.numerator ;
+        int NewDenominator = r1.denominator* r2.denominator ;
+
+        return new Rational(NewNumerator ,NewDenominator);
         // YOUR CODE HERE
-        return null; // Remove this line when implemented
+        //return null; // Remove this line when implemented
     }
 
     // TODO: Instance method - this / other
@@ -83,13 +99,32 @@ public class Rational {
         // YOUR CODE HERE
         // HINT: Division is multiplication by reciprocal
         // Don't forget to check if other.numerator is zero!
-        return null; // Remove this line when implemented
+       // return null; // Remove this line when implemented
+        if (other.numerator == 0 )
+        {
+            throw new ArithmeticException("cannot divide ") ;
+        }
+        int NewNumerator = this.numerator*other.denominator ;
+        int NewDenominator = this.denominator*other.numerator ;
+        return new Rational(NewNumerator ,NewDenominator);
+
+
+
     }
 
     // TODO: Static method - r1 / r2
     public static Rational divide(Rational r1, Rational r2) {
         // YOUR CODE HERE
-        return null; // Remove this line when implemented
+        if (r2.numerator == 0 )
+        {
+            throw new ArithmeticException("cannot divide ") ;
+        }
+        int NewNumerator = r1.numerator * r2.denominator ;
+        int NewDenominator = r1.denominator * r2.numerator ;
+        return new Rational(NewNumerator ,NewDenominator);
+
+
+        //return null; // Remove this line when implemented
     }
 
     //  PROVIDED - String representation