#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <stdlib.h>
#include <conio.h>
#include <malloc.h>
#include <stdio.h>



int main() {
    system("chcp 1251");
    system("cls");
    double **a;
    char* c = (char*)malloc(100 * sizeof(char));
    int i, j, n = 0;
    printf("Vvedite rang matricy:\n");
    scanf("%s", c);
    n = atoi(c);
    a = (double**)malloc((n)*sizeof(double*));
    for (i = 0; i<n; i++)
    {
        a[i] = (double*)malloc((n+1)*sizeof(double));
        for (j = 0; j<=n; j++)
        {
            printf("a[%d][%d] = ", i, j);
            scanf("%s", c);
            a[i][j] = atof(c);
        }
    }
    for (i = 0; i<n; i++)
    {
        for (j = 0; j<=n; j++)
        {
            printf("%f ", a[i][j]);
        }
        printf("\n");
    }
    printf("nachalo raboti programmi:\n");

    for (i = 0; i < n; i++)
    {
        double koef1 = a[i][i];
        for (int j = 0; j <= n; j++){

            a[i][j] = a[i][j] / koef1;
        }

        for (int k = i + 1; k < n; k++)
        {
            double koef = a[k][i];
            for (int j = 0; j <= n; j++){
                a[k][j] = a[k][j] - koef* a[i][j];
            }
        }
    }

    for (i = 0; i < n; i++)
    {
        for (j = 0; j <= n; j++)
        {
            printf("%f ", a[i][j]);
        }
        printf("\n");
    }
    printf("pristupayu k x\n");
    double *x;
    x = (double*)malloc(n*sizeof(double));

    for (i = 0; i < n; i++)
    {
        x[i] = 0.0;
    }

    for (i = n-1; i >= 0; i--)
    {
        x[i] = a[i][n];
        for (j = 0; j < n; j++)
        {
            if (i != j) x[i] = x[i] - a[i][j]*x[j];
        }
    }
    printf("itogo:\n");
    printf("\n");
    for (j = 0; j < n; j++)
    {
        printf("x[%d]= ", j);
        printf("%f", x[j]);

    }

    free(a);
    free(x);
    free(c);
    _getch();
    return 0;
}