Gaus.cpp

#include <iostream>
#include <math.h>
using namespace std;
double mat[10][10];
double vec[10];
double e[10];
int n;
double x, a, b;

int main() {
    cout << "Enter number of unknown" << endl;
    cout << "n=";
    cin >> n;
    for (int i=1; i<=n; i++) {
        b= vec[i];
        for (int j=1; j<=n; j++) {
            a = mat[i][j];
            cout << "Enter coeficients of system left side" << endl;
            cout << "a[" << i << "," << j << "]=";
            cin >> a;
        }
        cout << "Enter coeficients of system right side" << endl;
        cout << "a[" << i << "," << n+1 << "]=";
        cin >> b;
    }
    if (n == 1) {
        x = b/a;
       cout << "x=" << x;
    }
    else if (mat[1][1] != 1) {
        for (int j=1; j<=n; j++) {
            mat[1][j] = mat[1][j]/mat[1][1];
        }
    }
        for (int i=1; i<=n; i++) {
            for (int j=1; j<=n; j++) {
                while (i>j) {
                mat[i][j] =mat[i][j] - mat[1][j]*mat[i][1];
                }
            }
            }
        e[n] = vec[n]/mat[n][n];
        for (int i=n; i>0; i=i-1) {
            for (int j = n; j >0; j=j-1) {
                mat[n-i][j] =mat[n-i][j]*e[i];

            }
        }
    return 0;
}