62 lines
1.7 KiB
Java
62 lines
1.7 KiB
Java
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package Maths;
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import java.util.*;
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/*
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* @author Ojasva Jain
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* Determinant of Matrix Wikipedia link : https://en.wikipedia.org/wiki/Determinant
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*/
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public class DeterminantOfMatrix
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{
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// Determinant calculator
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//@return determinant of the input matrix
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static int determinant(int a[][], int n)
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{
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int det = 0, sign = 1, p = 0, q = 0;
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if(n==1)
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{
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det = a[0][0];
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}
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else
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{
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int b[][] = new int[n-1][n-1];
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for(int x = 0 ; x < n ; x++)
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{
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p=0;q=0;
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for(int i = 1;i < n; i++)
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{
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for(int j = 0; j < n;j++)
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{
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if(j != x)
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{
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b[p][q++] = a[i][j];
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if(q % (n-1) == 0)
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{
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p++;
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q=0;
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}
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}
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}
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}
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det = det + a[0][x] *determinant(b, n-1) * sign;
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sign = -sign;
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}
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}
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return det;
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}
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//Driver Method
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public static void main(String [] args){
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Scanner in = new Scanner(System.in);
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//Input Matrix
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System.out.println("Enter matrix size (Square matrix only)");
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int n = in.nextInt();
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System.out.println("Enter matrix");
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int a [][] = new int [n][n];
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for(int i=0;i<n;i++){
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for(int j=0;j<n;j++){
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a[i][j] = in.nextInt();
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}
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}
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System.out.println(determinant(a, n));
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}
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}
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