複合多項式錯誤

Question

我有一個問題需要完成使用Java多項式。我設置了所有的代碼，它看起來沒問題，但是用我的複合方法，我收到了不同於預期的輸出。

class Polyonmial 
{ 
    final static private int mantissa=52; 
    final static private double epsilon=Math.pow(2.0,-mantissa); 
    private double coefficient=0.0; 
    private int power=0; 
    private Polynomial successor=null; 
    public Polynomial(double coefficient, int power) 
    { 
     if (Double.isNaN(coefficient)) return; 
     if (Math.abs(coefficient)<epsilon) return; 
     if (power<0) return; 
     this.coefficient=coefficient; 
     this.power=power; 
    } 

final public double coefficient(int power) 
{ 
    if (power<0) return 0.0; 
    Polynomial traverser=this; 
    do 
    { 
     if (traverser.power<power) return 0.0; 
     if (traverser.power==power) return traverser.coefficient; 
     traverser=traverser.successor; 
    } 
    while (traverser!=null); 
    return 0.0; 
} 

final public Polynomial composite(Polynomial that) 
{ 
    if (that==null) return null; 
    Polynomial thisClone = this.clone(); 
    Polynomial thatClone = that.clone(); 
    Polynomial temp = new Polynomial(0.0,0); 
    Polynomial result = new Polynomial(0.0,0); 

    while(thisClone != null) 
    { 
     if (thisClone.power == 0) 
     { 
      temp.coefficient = 1.0; 
      temp.power = 0; 
     } 
     else 
     { 
      if (thisClone.power == 1) 
      temp = thatClone; 
     } 
     //System.out.println("temp:"+temp); 

     while(temp != null) 
     { 
      temp.coefficient = thisClone.coefficient*temp.coefficient; 
      result = result.plus(temp); 
      temp = temp.successor; 
     } 
     temp = new Polynomial(0.0,0); 
     thisClone=thisClone.successor; 
    } 
    return result; 
} 

final public Polynomial[] dividedBy(Polynomial that) 
{ 
    if (that==null) return null; 
    if (that.coefficient==0.0) return null; 
    Polynomial quotient=new Polynomial(0.0,0); 
    Polynomial remainder=this.clone(); 

    Polynomial traverser = this.clone(); 
    Polynomial resultoftemp = new Polynomial(0.0, 0); 
    Polynomial temp = new Polynomial(0.0, 0); 

    double thiscoffe = this.coefficient(this.degree()); 
    double thatcoffe = that.coefficient(that.degree()); 

    if(that.coefficient !=0 && that.power !=0) 
    { 
     quotient.coefficient = thatcoffe/thiscoffe; 
     quotient.power = that.power - this.power; 
    } 

    while(traverser !=null) 
    { 
     temp.power = quotient.power + traverser.power; 
     temp.coefficient = quotient.coefficient * traverser.coefficient; 
     traverser=traverser.successor; 

     resultoftemp = resultoftemp.plus(temp); 

     remainder = that.minus(resultoftemp); 
    } 

    Polynomial[] result=new Polynomial[2]; 
    result[0]=quotient; 
    result[1]=remainder; 
    return result; 
} 

final public Polynomial integrate() 
{ 
    if (this.coefficient==0.0) return new Polynomial(0.0,0); 
    Polynomial result=this.clone(); 

    Polynomial temp = new Polynomial(0.0, 0); 
    Polynomial rstemp = new Polynomial(0.0, 0); 

    while(result!=null) 
    { 
     rstemp.power = result.power + 1; 
     rstemp.coefficient = result.coefficient/(result.power +1); 
     result = result.successor; 
     temp = temp.plus(rstemp); 
    } 
    return result; 
} 

final public Polynomial minus(Polynomial that) 
{ 
    if (that==null) return null; 
    if (this.equals(that)) return new Polynomial(0.0,0); 
    Polynomial result=this.clone(); 
    if (that.coefficient==0.0) return result; 
    Polynomial traverser=that; 
    do 
    { 
     add(result,-traverser.coefficient,traverser.power); 
     traverser=traverser.successor; 
    } 
    while (traverser!=null); 
    return result; 
} 

final public int powerMax() 
{ 
    int max=Integer.MIN_VALUE; 
    Polynomial traverser=this; 
    do 
    { 
     if (max<traverser.power) max=traverser.power; 
     traverser=traverser.successor; 
    } 
    while (traverser!=null); 
    return max; 
} 

final public int powerMin() 
{ 
    int min=Integer.MAX_VALUE; 
    Polynomial traverser=this; 
    do 
    { 
     if (min>traverser.power) min=traverser.power; 
     traverser=traverser.successor; 
    } 
    while (traverser!=null); 
    return min; 
} 

} 

在我的預期輸出文件，我應該得到這樣的：

(-1.0*X^1+1.0).composite(-1.0*X^1+1.0)= 
1.0*X^1 

而是我得到：

(-1.0*X^1+1.0).composite(-1.0*X^1+1.0)= 
1.0*X^1+1.0 

任何提示或幫助是極大的讚賞。

Answer 1

我稍微改變了你的複合方法，所以（在邏輯上等價的，支架移動和println添加）：

final public Polynomial composite(Polynomial that) { 
    if (that==null) return null; 
    Polynomial thisClone = this.clone(); 
    Polynomial thatClone = that.clone(); 
    Polynomial temp = new Polynomial(0.0,0); 
    Polynomial result = new Polynomial(0.0,0); 

    while(thisClone != null) { 
     System.out.println("composite with term degree: " + thisClone.power); 
     if (thisClone.power == 0) { 
      temp.coefficient = 1.0; 
      temp.power = 0; 
     } else if (thisClone.power == 1) { 
      temp = thatClone; 
     } else { 
      for(int i=2; i<=thisClone.power; i++) { 
       temp = temp.plus(thatClone.times(thatClone)); 
      } 
     } 
     System.out.println("temp heading in: " + temp); 

     while(temp != null) { 
      temp.coefficient = thisClone.coefficient*temp.coefficient; 
      result = result.plus(temp); 
      temp = temp.successor; 
     } 
     System.out.println("result so far: " + result); 
     temp = new Polynomial(0.0,0); 
     thisClone=thisClone.successor; 
    } 
    return result; 
} 

和用於例如(-1.0*X^1+1.0).composite(-1.0*X^1+1.0)，這是輸出：

複合材料term degree：1
temp heading in：-1.0 * X^1 + 1.0
目前爲止的結果：1.0 * X^1
複合材料的術語度數：0
溫度在標題：1.0
結果至今：1.0 * X^1 + 1.0

我是正確相信那首 「​​結果又」 應爲「-1.0 * X^1-1.0 「？

如果是這樣，讓我們​​來看看下面的循環：

 while(temp != null) { 
      temp.coefficient = thisClone.coefficient*temp.coefficient; 
      result = result.plus(temp); 
      temp = temp.successor; 
     } 

我覺得這是你的問題：result = result.plus(temp)不加入只是「本期」來臨時，也是繼任者任期。但是，通過將它設置爲等於它的後繼，然後再次執行，您可以循環使用temp！

我認爲解決的辦法是這樣的（先計算所有的臨時條款，那麼更新結果）：

Polynomial looptemp = temp; 
    while(looptemp != null) { 
     looptemp.coefficient = thisClone.coefficient*looptemp.coefficient; 
     looptemp = looptemp.successor; 
    } 
    result = result.plus(temp); 

最起碼，它適用於單例如我試過了。