Calculating Matrix Determinant with C++

About Program

This program can calculate the determinant of any square matrix. I used the STL(std::vector) to store the matrices. To calculate the determinant, I used recursive function concept.

	/*Eong Koungmeng 19/9/2022*/
	#include<iostream>
	#include<vector>
	#include <assert.h>
	//This function can calculate determinant of any square matrix
	float Determinant(std::vector<std::vector<float>>(matrix))
	{
	int rows = matrix.size();
	int cols = matrix[0].size();
	assert(rows == cols); //Raise error is rows != cols
	if (rows == 2)
	{
	return matrix[0][0] * matrix[1][1] - matrix[0][1] * matrix[1][0]; //2x2 Matrix
	}
	else
	if (rows > 2) //For 3x3 matrix and bigger
	{
	int sign = 1;
	float sum = 0;
	for (int i = 0; i < rows; i++)
	{
	std::vector<std::vector<float>>subMatrix(rows - 1, std::vector<float>(rows - 1)); //Create subMatrix in order to calculate minor
	for (int j = 1; j < rows; j++)
	{
	bool b = false;
	for (int k = 0; k < rows; k++)
	{
	if (k == i)
	{
	b = true;
	continue;
	}
	subMatrix[j - 1][k - b] = matrix[j][k];
	}
	}
	sum += sign * matrix[0][i] * Determinant(subMatrix);
	sign *= -1;
	}
	return sum;
	}
	else {
	return matrix[0][0];
	}
	}
	int main()
	{
	//Input any matrix here
	std::vector<std::vector<float>>(matrixA) = { {1, 3, 5, 9}, {1, 3, 1, 7}, {4, 3, 9, 7}, {5, 2, 0, 9} };
	std::cout << "The determinant of the matrix is: " << Determinant(matrixA) << std::endl;
	std::cin.get();
	}

view raw Determinant.cpp hosted with ❤ by GitHub

The output