import java.util.Scanner;
/*求矩阵的伴随矩阵*/
public class ajoint_matrix {
private static float[][] get_complement(float[][] data, int i, int j) {
/* x和y为矩阵data的行数和列数 */
int x = data.length;
int y = data[0].length;
/* data2为所求剩余矩阵 */
float data2[][] = new float[x - 1][y - 1];
for (int k = 0; k < x - 1; k++) {
if (k < i) {
for (int kk = 0; kk < y - 1; kk++) {
if (kk < j) {
data2[k][kk] = data[k][kk];
} else {
data2[k][kk] = data[k][kk + 1];
}
}
} else {
for (int kk = 0; kk < y - 1; kk++) {
if (kk < j) {
data2[k][kk] = data[k + 1][kk];
} else {
data2[k][kk] = data[k + 1][kk + 1];
}
}
}
}
return data2;
}
/* 计算矩阵行列式 */
private static float cal_det(float[][] data) {
float ans=0;
/*若为2*2的矩阵可直接求值并返回*/
if(data[0].length==2){
ans=data[0][0]*data[1][1]-data[0][1]*data[1][0];
}
else{
for(int i=0;i
/*若矩阵不为2*2那么需求出矩阵第一行代数余子式的和*/
float[][] data_temp=get_complement(data, 0, i);
if(i%2==0){
/*递归*/
ans=ans+data[0][i]*cal_det(data_temp);
}
else{
ans=ans-data[0][i]*cal_det(data_temp);
}
}
}
return ans;
}
/*计算矩阵的伴随矩阵*/
private static float[][] ajoint(float[][] data) {
int M=data.length;
int N=data[0].length;
float data2[][]=new float[M][N];
for(int i=0;i
for(int j=0;j
if((i+j)%2==0){
data2[i][j]=cal_det(get_complement(data, i, j));
}
else{
data2[i][j]=-cal_det(get_complement(data, i, j));
}
}
}
/*将矩阵转置*/
return trans(data2);
}
/*转置矩阵*/
private static float [][]trans(float[][] data){
int i=data.length;
int j=data[0].length;
float[][] data2=new float[j][i];
for(int k2=0;k2
for(int k1=0;k1
data2[k2][k1]=data[k1][k2];
}
}
return data2;
}
public static void main(String[] args) {
/* 输入原矩阵矩阵 */
Scanner scan = new Scanner(System.in);
System.out.println("输入矩阵的行数和列数");
int x = scan.nextInt();
int y = scan.nextInt();
float data[][] = new float[x][y];
System.out.println("输入矩阵");
for (int k = 0; k < x; k++) {
for (int kk = 0; kk < y; kk++) {
data[k][kk] = scan.nextFloat();
}
}
System.out.println("该矩阵的伴随矩阵为：");
float data2[][]=new float[x][y];
data2=ajoint(data);
for(int i=0;i
{
for(int j=0;j
System.out.print(data2[i][j]+" ");
}
System.out.println();
}
}
}
