RosettaCodeData/Task/Matrix-arithmetic/Java/matrix-arithmetic-1.java

56 lines
1.3 KiB
Java

import java.util.Scanner;
public class MatrixArithmetic {
public static double[][] minor(double[][] a, int x, int y){
int length = a.length-1;
double[][] result = new double[length][length];
for(int i=0;i<length;i++) for(int j=0;j<length;j++){
if(i<x && j<y){
result[i][j] = a[i][j];
}else if(i>=x && j<y){
result[i][j] = a[i+1][j];
}else if(i<x && j>=y){
result[i][j] = a[i][j+1];
}else{ //i>x && j>y
result[i][j] = a[i+1][j+1];
}
}
return result;
}
public static double det(double[][] a){
if(a.length == 1){
return a[0][0];
}else{
int sign = 1;
double sum = 0;
for(int i=0;i<a.length;i++){
sum += sign * a[0][i] * det(minor(a,0,i));
sign *= -1;
}
return sum;
}
}
public static double perm(double[][] a){
if(a.length == 1){
return a[0][0];
}else{
double sum = 0;
for(int i=0;i<a.length;i++){
sum += a[0][i] * perm(minor(a,0,i));
}
return sum;
}
}
public static void main(String args[]){
Scanner sc = new Scanner(System.in);
int size = sc.nextInt();
double[][] a = new double[size][size];
for(int i=0;i<size;i++) for(int j=0;j<size;j++){
a[i][j] = sc.nextDouble();
}
sc.close();
System.out.println("Determinant: "+det(a));
System.out.println("Permanent: "+perm(a));
}
}