Kód: Vybrať všetko

#include <iostream>
#include <vector>
#include <algorithm>

//deklaracie
using namespace std;
typedef vector<double>Vect;
typedef vector<Vect>Matr;
int fact(int a),i,j,p,nb;
double determ,matica[50][50],pomocna[50][50],vysledky[50],D[50];

//vypocet determinantu pre lubovolnu stvorcovu maticu
int det(){
	int counter = 0,ve1 = 0;Vect row(nb);
	Vect determinant;
	Matr a;
	double product = 1;
    determ = 0;
    //nacitanie matice
	for(i = 0; i < nb; i++){
		for(j = 0; j < nb; j++)
			row[j]=matica[i][j];
		a.push_back(row);
	}
	//vypocet determinantu
	vector<int>vec;
	for(i = 1; i <= nb; i++)
		vec.push_back(i);
	vector<int>::iterator iter1 = vec.begin();
	vector<int>::iterator iter2 = vec.end();
	for(i = 0; i < fact(nb); i++){
		  vector<int>vec1(nb);
		  copy(vec.begin(), vec.end(), vec1.begin());
		  for(int i = 0; i < vec1.size(); i++)
			  for(int j = i; j < vec1.size(); j++)
				  if(vec1[j]<vec1[i])
					  counter++;
		  for(int w = 0; w < nb; w++){
			  ve1 = (vec1[w])-1;
			  product *= (a[w][ve1]);
		  }	
		  if(counter%2!=0)
			  product = (- product);
		  determinant.push_back(product);
          counter = 0;
		  product = 1;
		  next_permutation(iter1, iter2);
	}
	//zapisanie determinantu do premennej
	for(int x = 0; x < determinant.size(); x++)
		determ += determinant[x];
}
//pomocna funkcia pre vypocet determinantu
int fact(int a){
	if(a<=1)
		return a;
	return (a * fact(a - 1));
}
//hlavny program
int main(){
    int p,r;
    cout << "Zadaj pocet rovnic: ";
	cin >> nb;
	printf("Rovnicu (napr.) ax + by =c zadaj v tvare a b c.\n\n");
    //nacitanie rovnic (matice a vysledkov) z klavesnice
    for(i = 0; i < nb; i++){
        cout << "Zadaj " << i+1 << ".rovnicu: ";  
		for(j = 0; j < nb+1; j++){
			if(j!=nb)
                cin >> matica[i][j];
            else
                cin >> vysledky[i];
        }
    }
    //vypocet a zistenie ci hlavny D nie je nulovy, pretoze delit nulou sa neda
    det();
    if(determ==0){
       printf("Determinant je rovny 0. Neda sa pouzit Cramer!\n");
       system("pause");
       exit(0);
    }
    //ak nie je rovny 0 tak program pokracuje
    D[0]=determ;
    //vytvorenie pomocnej matice
    for(p = 0; p < nb; p++)
       for(j = 0; j < nb; j++)
          pomocna[p][j]=matica[p][j];
    //vypis zakladnej matice a jej determinantu
    for(r = 0; r < nb; r++){
       cout<<endl;
       for(j = 0; j < nb; j++)
          cout << matica[r][j];
    }
    cout << endl << "D=" << D[0]<<endl;
    //vymena stlpcov v matici za vektor vysledkov a vypocet determinantov
    for(p=0;p<nb;p++){               
       for(j = 0; j < nb; j++)
          matica[j][p]=vysledky[j];
       det();
       D[p+1]=determ;
       for(r = 0; r < nb; r++){
		  cout<<endl;
          for(j = 0; j < nb; j++)
             cout << matica[r][j];
       }
       cout << endl << "D["<<p+1<<"]=" << D[p+1] << endl;
       for(r = 0; r < nb; r++)
		  for(j = 0; j < nb; j++)
             matica[r][j] = pomocna[r][j];
    }
    //Pouzitie cramerovho pravidla: delenie determinantov
    printf("\nVysledny vektor hodnot je:\n");
    for(i=0;i<nb;i++)
       cout<<i+1<<".hodnota: "<<D[i+1]<<" / "<<D[0]<<" alebo "<<D[i+1]/D[0]<<endl;
    printf("\n");
    system("pause");
}