How to simplify an equation by using min amount of if block in Java?

You could use a switch statement to return an object with the values. Here I am using a record as an immutable class. It could also be a regular class.

record Data<T> (T A, T B, T C) {}

Data<Integer> d = getValues(10.6, 10,20,30);
System.out.println(d);
Data<String> d2 = getValues(9.3, "One","Two","Three");
System.out.println(d2);

prints

Data[A=30, B=10, C=20]
Data[A=Two, B=One, C=Three]

• casting q to an int will select the correct case
• then just return the object associated with the value of q
• Exception will be thrown if q is out of range.

public static <T> Data<T> getValues(double q, T x, T y, T z) {           
   return switch((int)(q/5)) {
         case 0 -> new Data<>(y,x,z);
         case 1 -> new Data<>(y,x,z);
         case 2 -> new Data<>(z,x,y);
         case 3 -> new Data<>(z,y,x);
         case 4 -> new Data<>(y,z,x);
         case 5 -> new Data<>(x,z,y);
         default -> throw new IllegalArgumentException("Argument out of range q = " + q);
   
     };
}

</details>



# 答案2
**得分**: 1

```java
假设 x、y 和 z 的值相对恒定，您可以创建一个映射将 q 值转化为 A、B、C 的特定分配。

    Map<Long,Assignment> map = new HashMap<>();
    map.put(0, new Assignment(x,y,z));
    map.put(1, new Assignment(y,x,z));
    ...
    map.put(5, new Assignment(x,z,y));
    
    public Assignment getAssignment(double q) {
      // 超出范围的 q 值返回 null
      return map.get((long)Math.floor(q));
    }

Map<Long,Assignment> map = new HashMap<>();
map.put(0, new Assignment(x,y,z));
map.put(1, new Assignment(y,x,z));
...
map.put(5, new Assignment(x,z,y));

public Assignment getAssignment(double q) {
  // out of range values of q return null
  return map.get((long)Math.floor(q));
}

答案3

得分: 1

public class Foo {
private static final List library;
static {
library = new ArrayList();
library.add(new Foo(x, y, z, 0, 1));
library.add(new Foo(y, x, z, 1, 2));
library.add(new Foo(z, x, y, 2, 3));
library.add(new Foo(z, y, x, 3, 4));
library.add(new Foo(y, z, x, 4, 5));
library.add(new Foo(x, z, y, 5, 6));
};
public static Foo get(double val) {
for(Foo foo : library) {
if(foo.lower <= val && foo.upper > val)
return foo;
}
return null;
}
public final Object A,B,C;
private final double lower,upper;
private Foo(Object A, Object B, Object C, double lower, double upper) {
this.A = A;
this.B = B;
this.C = C;
this.lower = lower;
this.upper = upper;
}
}

Then you can access your values like this

Foo foo = Foo.get(1.5d);
foo.A; // y

public class Foo {
	private static final List<Foo> library;
	static {
		library = new ArrayList<Foo>();
		library.add(new Foo(x, y, z, 0, 1));
		library.add(new Foo(y, x, z, 1, 2));
		library.add(new Foo(z, x, y, 2, 3));
		library.add(new Foo(z, y, x, 3, 4));
		library.add(new Foo(y, z, x, 4, 5));
		library.add(new Foo(x, z, y, 5, 6));
	};
	public static Foo get(double val) {
		for(Foo foo : library) {
			if(foo.lower <= val && foo.upper > val)
				return foo;
		}
		return null;
	}
	public final Object A,B,C;
	private final double lower,upper;
	private Foo(Object A, Object B, Object C, double lower, double upper) {
		this.A = A;
		this.B = B;
		this.C = C;
		this.lower = lower;
		this.upper = upper;
	}
}

Foo foo = Foo.get(1.5d);
foo.A; // y