Finding the DETERMINANT in C++

Asked By asquare25 50 points N/A Posted on - 03/20/2012

I need to build up a code where I can find the DETERMINANT of (nxn) matrix in C++, please assume the given matrix and also show the working step-by-step so that I can understand how it is done … plus The program asks the user which method to follow:
|1 0 0 9 8|
|2 1 0 7 6|
|3 2 1 5 3|
|0 0 0 7 4|
|0 0 0 5 3|
METHODS: Properties of DETERMINANTS.

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• Question Category: C++

Best Answer by Estillero State

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Answered By Estillero State 5 points N/A #127245

Finding the DETERMINANT in C++

Hi Asquare25,

 

Take a look at this sample code:

 

// prob_4.cpp : Defines the entry point for the console application.

//

 

#include <iostream>

#include <vector>

#include <algorithm>

using namespace std;

 

typedef vector<double>Vect;

typedef vector<Vect>Matrix;

 

unsigned int fact(unsigned int v_mat);

 

int main()

{

 

unsigned int i;

int counter = 0;

unsigned int i_row_col_col = 0;

cout << " Enter number of v_row_cols or columns :n";

cin >> i_row_col_col;

 

cout << " Enter the square Matrix :n";

Vect v_row_col(i_row_col_col);

Vect v_determinant;

Matrix v_mat;

double product = 1;

int determ = 0;

int ve1 = 0;

 

for(i = 0; i < i_row_col_col; i++)

{

for(unsigned int j = 0; j < i_row_col_col; j++)

{

if(j<(i_row_col_col-1))

cout << " enter elementn";

else cout << " enter last element of this v_row_coln";

cin >> v_row_col[j];

}

v_mat.push_back(v_row_col);

}

 

vector<int>vec;

for(i = 1; i <= i_row_col_col; i++)

vec.push_back(i);

vector<int>::iterator iter1 = vec.begin();

vector<int>::iterator iter2 = vec.end();

 

 

for(unsigned int i = 0; i < fact(i_row_col_col); i++)

{

 vector<int>vec1(i_row_col_col);

 copy(vec.begin(), vec.end(), vec1.begin());

 for(unsigned int j = 0; j < (i_row_col_col); j++)

 for(unsigned int i = 0; i < vec1.size(); i++)

 {

 

 for(unsigned int j = i; j < vec1.size(); j++)

 {

 if(vec1[j]<vec1[i])

 counter++;

 }

 }

 

 for(unsigned int w = 0; w < i_row_col_col; w++)

 {

 ve1 = (vec1[w])-1;

 product *= (v_mat[w][ve1]);

 }

 if(counter%2!=0)

 product = (- product);

 

 v_determinant.push_back(product); 

 

          counter = 0;

 product = 1;

 next_permutation(iter1, iter2);

}

 

for(unsigned int x = 0; x < v_determinant.size(); x++)

{

determ += (int)v_determinant[x];

}

 

for(i = 0; i < i_row_col_col; i++)//print the Matrix

{

cout << endl;

for(unsigned int j = 0; j < i_row_col_col; j++)

{

cout << v_mat[i][j] << " ";

}

}

cout << endl;

cout << " The determinant is :";

cout << determ << endl;

 

  system("pause");

    return 0;

}

// get factorial of v_mat

unsigned int fact(unsigned int i_element)

{

if(i_element<=i_element)

{

return i_element;

}

return (i_element * fact(i_element – 1));

}

 

About Estillero State

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• Posted on - 04/17/2012
• Question Category: C++

Answered By zack lee 10 points N/A #127246

Finding the DETERMINANT in C++

I had been looking for a method to find determinant in C++. Thankfully, I found a solution here! I tried the program given by the expert and did run it. It was 100% right. So then I studied the program and now I know how to write a program for finding determinant. Thank you so much.

Lee

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• Posted on - 06/20/2012
• Question Category: C++