JAVA 31

package matrix;

import java.util.Arrays;


public class IntMatrix {

	
	int[][] data;

	
	public IntMatrix(int paraRows, int paraColumns) {
		data = new int[paraRows][paraColumns];
	}// Of the first constructor

	
	public IntMatrix(int[][] paraData) {
		data = new int[paraData.length][paraData[0].length];
		// Copy elements.
		for (int i = 0; i < data.length; i++) {
			for (int j = 0; j < data[0].length; j++) {
				data[i][j] = paraData[i][j];
			} // Of for j
		} // Of for i
	}// Of the second constructor


	public IntMatrix(IntMatrix paraMatrix) {
		this(paraMatrix.getData());
	}// Of the third constructor

	
	public static IntMatrix getIdentityMatrix(int paraRows) {
		IntMatrix resultMatrix = new IntMatrix(paraRows, paraRows);
		for (int i = 0; i < paraRows; i++) {
			// According to access control, resultMatrix.data can be visited
			// directly.
			resultMatrix.data[i][i] = 1;
		} // Of for i
		return resultMatrix;
	}// Of getIdentityMatrix

	
	public int getRows() {
		return data.length;
	}// Of getRows

	
	public int getColumns() {
		return data[0].length;
	}// Of getColumns

	
	@Override
	public String toString() {
		return Arrays.deepToString(data);
	}

	
	public void setValue(int paraRow, int paraColumn, int paraValue) {
		data[paraRow][paraColumn] = paraValue;
	} // Of setValue

	
	public int getValue(int paraRow, int paraColumn) {
		return data[paraRow][paraColumn];
	}// Of getValue

	
	public int[][] getData() {
		return data;
	}// Of getData

	
	public static IntMatrix multiply(IntMatrix paraIntMatrix1, IntMatrix paraIntMatrix2) throws Exception {
		int[][] tempData1 = paraIntMatrix1.data;
		int[][] tempData2 = paraIntMatrix2.data;

		if (tempData1[0].length != tempData2.length) {
			throw new Exception("Cannot multiply matrices: " + tempData1[0].length + " vs. " + tempData2.length + ".");
		} // Of if

		// Step 2. Allocate space.
		int[][] resultData = new int[tempData1.length][tempData2[0].length];

		// Step 3. Multiply.
		for (int i = 0; i < tempData1.length; i++) {
			for (int j = 0; j < tempData2[0].length; j++) {
				for (int k = 0; k < tempData1[0].length; k++) {
					resultData[i][j] += tempData1[i][k] * tempData2[k][j];
				} // Of for k
			} // Of for j
		} // Of for i

		// Step 4. Construct the matrix object.
		IntMatrix resultMatrix = new IntMatrix(resultData);

		return resultMatrix;
	}// Of multiply

	
	public void add(IntMatrix paraMatrix) throws Exception {
		// Step 1. Get the data of the given matrix.
		int[][] tempData = paraMatrix.getData();

		// Step 2. Size check.
		if (data.length != tempData.length) {
			throw new Exception(
					"Cannot add matrices. Rows not match: " + data.length + " vs. " + tempData.length + ".");
		} // Of if
		if (data[0].length != tempData[0].length) {
			throw new Exception(
					"Cannot add matrices. Rows not match: " + data[0].length + " vs. " + tempData[0].length + ".");
		} // Of if

		// Step 3. Add to me.
		for (int i = 0; i < data.length; i++) {
			for (int j = 0; j < data[0].length; j++) {
				data[i][j] += tempData[i][j];
			} // Of for j
		} // Of for i
	}// Of add

	
	public static IntMatrix add(IntMatrix paraMatrix1, IntMatrix paraMatrix2) throws Exception {
		// Step 1. Clone the first matrix.
		IntMatrix resultMatrix = new IntMatrix(paraMatrix1.data);

		// Step 2. Add the second one.
		resultMatrix.add(paraMatrix2);

		return resultMatrix;
	}// Of add

	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		IntMatrix tempMatrix1 = new IntMatrix(3, 3);
		tempMatrix1.setValue(0, 1, 1);
		tempMatrix1.setValue(1, 0, 1);
		tempMatrix1.setValue(1, 2, 1);
		tempMatrix1.setValue(2, 1, 1);
		System.out.println("The original matrix is： " + tempMatrix1);

		IntMatrix tempMatrix2 = null;
		try {
			tempMatrix2 = IntMatrix.multiply(tempMatrix1, tempMatrix1);
		} catch (Exception ee) {
			System.out.println(ee);
		} // Of try
		System.out.println("The square matrix is： " + tempMatrix2);

		IntMatrix tempMatrix3 = new IntMatrix(tempMatrix2.data);
		try {
			tempMatrix3.add(tempMatrix1);
		} catch (Exception ee) {
			System.out.println(ee);
		} // Of try
		System.out.println("The connectivity matrix is： " + tempMatrix3);
	}// Of main

}// Of class IntMatrix

代码要具有大局观，用其他方法可以实现功能，但仅仅是对于当前代码，后序加入更多代码体现出功能性。