首先看一下預覽截圖:
下面的程序來自Y.Daniel Liang老師的《Java語言程序設計~進階篇》,稍有一點改動。話不多說,直接上代碼:
package num;
abstract class GenericMatrix<E extends Number>{
//將矩陣元素相加的抽象方法;
protected abstract E add(E o1, E o2);
//將矩陣的兩個元素相乘的抽象方法
protected abstract E multiply(E o1, E o2);
//定義零矩陣的抽象方法
protected abstract E zero();
//將兩個矩陣相加,用泛型E來表示類,所以方法是非靜態的;
public E[][] addMatrix(E[][] matrix1, E[][] matrix2){
//檢查矩陣matrix1和矩陣matrix2的大小是否相等,matrix1.length爲行數,matrix1[0].length爲列數
if ((matrix1.length != matrix2.length) || (matrix1[0].length != matrix2[0].length)){
throw new RuntimeException("The matrices do not have the same size!");
}
//不能用泛型類型來創建數組,要用(E[][])來轉換才能創建數組;
E[][] result = (E[][])new Number[matrix1.length][matrix1[0].length];
for(int i=0;i<result.length;i++)
for(int j=0;j<result[i].length;j++) {
result[i][j]=add(matrix1[i][j],matrix2[i][j]);
}
return result;
}
public E[][] multiplyMatrix(E[][] matrix1, E[][] matrix2){
if (matrix1[0].length != matrix2.length){
throw new RuntimeException("The matrices do not have the same size!");
}
E[][] result = (E[][])new Number[matrix1.length][matrix2[0].length];
for(int i=0;i<result.length;i++) {
for(int j=0;j<result[0].length;j++) {
result[i][j]=zero();
for(int k=0;k<matrix1[0].length;k++) {
result[i][j]=add(result[i][j],multiply(matrix1[i][k],matrix2[k][j]));
}
}
}
return result;
}
public static void printResult(Number[][] m1,Number[][] m2,Number[][] m3,char op) {
for(int i=0;i<m1.length;i++) {
for(int j=0;j<m1[0].length;j++)
System.out.print(" "+m1[i][j]);
if(i==m1.length/2)
System.out.print(" "+op+ " ");
else
System.out.print(" ");
for(int j=0;j<m2.length;j++)
System.out.print(" "+m2[i][j]);
if(i==m1.length/2)
System.out.print(" = ");
else
System.out.print(" ");
for(int j=0;j<m3.length;j++)
System.out.print(m3[i][j]+" ");
System.out.println();
}
}
}
class IntegerMatrix extends GenericMatrix<Integer>{
//實現GenericMatrix中的add抽象方法
protected Integer add(Integer o1, Integer o2 ){
return o1+o2;
}
//實現GenericMatrix中的mltiply抽象方法
protected Integer multiply(Integer o1, Integer o2){
return o1*o2;
}
//實現GenericMatrix中的zero抽象方法
protected Integer zero(){
return 0;
}
}
//Double類類繼承了GenericMatrix<?extends Number>中的;
class DoubleMatrix extends GenericMatrix<Double>{
//實現GenericMatrix中的三個抽象方法;
protected Double add(Double d1,Double d2){
return d1+d2;
}
protected Double multiply(Double d1,Double d2){
return d1*d2;
}
protected Double zero(){
return 0.0;
}
}
public class GenericMatrixmain{
public static void main(String[] args){
//創建Integer數組
Integer[][] m1 = new Integer[][]{{1,2,3},{4,5,6},{7,8,9}};
Integer[][] m2 = new Integer[][]{{1,5,1},{2,4,2},{0,0,0}};
//創建IntegerMatrix實例;
IntegerMatrix integerMatrix = new IntegerMatrix();
System.out.println("m1+m2 is ");
GenericMatrix.printResult(m1,m2,integerMatrix.addMatrix(m1,m2),'+');
System.out.println("m1*m2 is ");
GenericMatrix.printResult(m1,m2,integerMatrix.multiplyMatrix(m1,m2),'*');
//創建Double數組
Double[][] d1 = new Double[][]{{1.1, 1.2, 1.3}, {2.1, 2.1, 2.1}, {3.1, 3.1, 3.1}};
Double[][] d2 = new Double[][]{{1.1, 2.1, 3.1}, {2.1, 2.1, 2.1}, {3.1, 3.1, 3.1}};
DoubleMatrix doubleMatrix = new DoubleMatrix();
System.out.println("d1+d2 is ");
GenericMatrix.printResult(d1,d2,doubleMatrix.addMatrix(d1,d2),'+');
System.out.println("d1*d2 is ");
GenericMatrix.printResult(d1,d2,doubleMatrix.multiplyMatrix(d1,d2),'*');
}
}
寫在後面:
最近幾天有點心力交瘁,害,不要在做一個任務之前想着放縱幾天,一放縱就不是幾天的問題,當你下定決心開始任務時,你發現放縱的這幾天,把身體搞的力不從心了。算是一個教訓了,靜水流深,加油!!!堅持下去!!!