Java问题中的多项式类
这个多项式类,特别是checkZero和differention方法,我遇到了麻烦。checkZero类应该查看多项式中是否有任何前导系数,如果有,它应该调整系数数组的大小。微分法应该找到多项式的导数,但我一直得到Java问题中的多项式类,java,arrays,Java,Arrays,这个多项式类,特别是checkZero和differention方法,我遇到了麻烦。checkZero类应该查看多项式中是否有任何前导系数,如果有,它应该调整系数数组的大小。微分法应该找到多项式的导数,但我一直得到ArrayIndexOutOfBounds错误 public class Polynomial { private float[] coefficients; public static void main (String[] args){ float
ArrayIndexOutOfBounds
错误
public class Polynomial {
private float[] coefficients;
public static void main (String[] args){
float[] fa = {3, 2, 4};
Polynomial test = new Polynomial(fa);
}
public Polynomial() {
coefficients = new float[1];
coefficients[0] = 0;
}
public Polynomial(int degree) {
coefficients = new float[degree+1];
for (int i = 0; i <= degree; i++)
coefficients[i] = 0;
}
public Polynomial(float[] a) {
coefficients = new float[a.length];
for (int i = 0; i < a.length; i++)
coefficients[i] = a[i];
}
public int getDegree() {
return coefficients.length-1;
}
public float getCoefficient(int i) {
return coefficients[i];
}
public void setCoefficient(int i, float value) {
coefficients[i] = value;
}
public Polynomial add(Polynomial p) {
int n = getDegree();
int m = p.getDegree();
Polynomial result = new Polynomial(Polynomial.max(n, m));
int i;
for (i = 0; i <= Polynomial.min(n, m); i++)
result.setCoefficient(i, coefficients[i] + p.getCoefficient(i));
if (i <= n) {
//we have to copy the remaining coefficients from this object
for ( ; i <= n; i++)
result.setCoefficient(i, coefficients[i]);
} else {
// we have to copy the remaining coefficients from p
for ( ; i <= m; i++)
result.setCoefficient(i, p.getCoefficient(i));
}
return result;
}
public void displayPolynomial () {
for (int i=0; i < coefficients.length; i++)
System.out.print(" "+coefficients[i]);
System.out.println();
}
private static int max (int n, int m) {
if (n > m)
return n;
return m;
}
private static int min (int n, int m) {
if (n > m)
return m;
return n;
}
public Polynomial multiplyCon (double c){
int n = getDegree();
Polynomial results = new Polynomial(n);
for (int i =0; i <= n; i++){ // can work when multiplying only 1 coefficient
results.setCoefficient(i, (float)(coefficients[i] * c)); // errors ArrayIndexOutOfBounds for setCoefficient
}
return results;
}
public Polynomial multiplyPoly (Polynomial p){
int n = getDegree();
int m = p.getDegree();
Polynomial result = null;
for (int i = 0; i <= n; i++){
Polynomial tmpResult = p.multiByConstantWithDegree(coefficients[i], i); //Calls new method
if (result == null){
result = tmpResult;
} else {
result = result.add(tmpResult);
}
}
return result;
}
public void checkZero(){
int newDegree = getDegree();
int length = coefficients.length;
float testArray[] = coefficients;
for (int i = coefficients.length-1; i>0; i--){
if (coefficients[i] != 0){
testArray[i] = coefficients[i];
}
}
for (int j = 0; j < testArray.length; j++){
coefficients[j] = testArray[j];
}
}
public Polynomial differentiate(){
int n = getDegree();
int newPolyDegree = n - 1;
Polynomial newResult = new Polynomial();
if (n == 0){
newResult.setCoefficient(0, 0);
}
for (int i =0; i<= n; i++){
newResult.setCoefficient(i, coefficients[i+1] * (i+1));
}
return newResult;
}
}
公共类多项式{
私有浮动系数;
公共静态void main(字符串[]args){
float[]fa={3,2,4};
多项式测试=新多项式(fa);
}
公共多项式(){
系数=新浮点数[1];
系数[0]=0;
}
公共多项式(整数次){
系数=新浮点数[度数+1];
对于(int i=0;i可能会有更多的问题,但您的区分方法有一个问题:
int n = getDegree();
...
Polynomial newResult = new Polynomial();
...
for (int i = 0; i <= n; i++)
{
newResult.setCoefficient(i, coefficients[i + 1] * (i + 1)); //This line
}
int n=getDegree();
...
多项式newResult=新多项式();
...
对于(int i=0;i首先,一些代码注释:
新数组在Java中自动初始化为0。这是不需要的
coefficients = new float[degree+1];
for (int i = 0; i <= degree; i++)
coefficients[i] = 0;
系数=新浮点数[度数+1];
对于(int i=0;i)哪一行引发异常?您以前没有问过这个问题吗?您发布的代码太多了。异常应该确切地告诉您哪一行是问题所在,发布该部分并在必要时展开。更好的是,使用调试器并逐步完成代码。
int i;
for (i = 0; i <= Polynomial.min(n, m); i++)
result.setCoefficient(i, coefficients[i] + p.getCoefficient(i));
if (i <= n) {
//we have to copy the remaining coefficients from this object
for ( ; i <= n; i++)
result.setCoefficient(i, coefficients[i]);
} else {
// we have to copy the remaining coefficients from p
for ( ; i <= m; i++)
result.setCoefficient(i, p.getCoefficient(i));
}
for (int i = 0; i <= result.getDegree(); i++)
result.setCoefficient(i,
i>n?0:coefficients[i] +
i>m?0:p.getCoefficient(i));
int n = getDegree();
....
for (int i =0; i<= n; i++){
newResult.setCoefficient(i, coefficients[i+1] * (i+1));
}