gistfile1.txt

// Informatik - Serie 8 - Skript-Aufgabe 81
// Program: inverse_matrix.cpp
// Invert a 3x3 matrix.
// Autor: Tim Menke Plestudent (Gruppe C)

#include <iostream>

int main()
{
  // Initialization
  float A[3][3];

  // Input
  std::cout << "Please input a 3x3 matrix A with real entries.\n";
 // i: Zeilen
  for (unsigned int i = 0; i < 3; ++i) {
    // j: Spalten --> Aij
    for (unsigned int j = 0; j < 3; ++j) {
      std::cin >> A[i][j];      
    }
  }

  std::cout << "\n\nA=\n";  
  for (int i = 0; i < 3; i++) {
    std::cout << "  " << A[i][0] << "\t" << A[i][1] << "\t" << A[i][2] << "\n";
  }

  // Compute determinant
  float det = 0;
  
  std::cout << "0det(A) = " << det << "\n";
  det += A[0][0]*A[1][1]*A[2][2];  

  std::cout << "1det(A) = " << det << "\n";
  det += A[0][1]*A[1][2]*A[2][0];  

  std::cout << "2det(A) = " << det << "\n";
  det += A[0][2]*A[1][0]*A[2][1];  

  std::cout << "3det(A) = " << det << "\n";
  det -= A[2][0]*A[1][1]*A[0][2];  

  std::cout << "4det(A) = " << det << "\n";
  det -= A[2][1]*A[1][2]*A[0][0];  

  std::cout << "5det(A) = " << det << "\n";
  det -= A[2][2]*A[1][0]*A[0][1];  

  std::cout << "6det(A) = " << det << "\n";

  //Output matrix A
  for (unsigned int i = 0; i < 3; ++i) {
    for (unsigned int j = 0; j < 3; ++j)
      std::cout << A[i][j] << " ";
    std::cout << "\n";
  }
}