Tropical algebra overloading: Difference between revisions
→{{header|Java}}
Line 504:
<syntaxhighlight>
import java.util.Optional;
public final class TropicalAlgebra {
public static void main(String[] aArgs) {
final Tropical a = new Tropical(-2);
final Tropical b = new Tropical(-1);
final Tropical c = new Tropical(-0.5);
final Tropical d = new Tropical(-0.001);
final Tropical e = new Tropical(0);
final Tropical f = new Tropical(1.5);
final Tropical g = new Tropical(2);
final Tropical h = new Tropical(5);
final Tropical i = new Tropical(7);
final Tropical j = new Tropical(8);
final Tropical k = new Tropical();
System.out.println("2 x -2 = " + g.multiply(a));
System.out.println("-0.001 + -Inf = " + d.add(k));
System.out.println("0 x -Inf = " + e.multiply(k));
System.out.println("1.5 + -1 = " + f.add(b));
System.out.println("-0.5 x 0 = " + c.multiply(e));
System.out.println();
System.out.println("5^7 = " + h.power(7));
System.out.println();
System.out.println("5 * ( 8 + 7 ) = " + h.multiply(j.add(i)));
System.out.println("5 * 8 + 5 * 7 = " + h.multiply(j).add(h.multiply(i)));
}
}
final class Tropical {
public Tropical(Number aNumber) {
if ( aNumber == null ) {
throw new IllegalArgumentException("Number cannot be null");
}
opt = Optional.of(aNumber);
}
public Tropical() {
opt = Optional.empty();
}
@Override
public String toString() {
if ( opt.isEmpty() ) {
return "-Inf";
}
String value = String.valueOf(opt.get());
final int index = value.indexOf(".");
if ( index >= 0 ) {
value = value.substring(0, index);
}
return value;
}
public Tropical add(Tropical aOther) {
if ( aOther.opt.isEmpty() ) {
return this;
}
if ( opt.isEmpty() ) {
return aOther;
}
if ( opt.get().doubleValue() > aOther.opt.get().doubleValue() ) {
return this;
}
return aOther;
}
public Tropical multiply(Tropical aOther) {
if ( opt.isPresent() && aOther.opt.isPresent() ) {
double result = opt.get().doubleValue() + aOther.opt.get().doubleValue();
return new Tropical(result);
}
return new Tropical();
}
public Tropical power(int aExponent) {
if ( aExponent <= 0 ) {
throw new IllegalArgumentException("Power must be positive");
}
Tropical result = this;;
for ( int i = 1; i < aExponent; i++ ) {
result = result.multiply(this);
}
return result;
}
private Optional<Number> opt;
}
</syntaxhighlight>
{{ out }}
<pre>
2 x -2 = 0
-0.001 + -Inf = -0
0 x -Inf = -Inf
1.5 + -1 = 1
-0.5 x 0 = -0
5^7 = 35
5 * ( 8 + 7 ) = 13
5 * 8 + 5 * 7 = 13
</pre>
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