#include <stdio.h>
#include <stdlib.h>

int main()
{
   int n, m,i,j,p,sloup;
   float array[20][21], array1[21];
   long double  x1, x2, x3,x,cons,cons1;

m=0;
cons=0;
cons1=0;

   printf("Zadejte pocet promennych:\n");
    if (scanf("%d",&n)!=1) {
      printf("Nespravny vstup.\n"); return (EXIT_FAILURE); }

m=n*n+n;

sloup=n+1;

   printf("Zadejte %d prvku matice:\n", m);
    for (i=0; i<n; i++) {
       for (j=0; j<n+1; j++) {

          if (scanf("%f",&array[i][j])!=1) {
      printf("Nespravny vstup.\n"); return (EXIT_FAILURE); }
          }

       }



for (p=0;p<=n-1;p++) {
 for (i=p;i<=n-1; i++) {
     cons=-array[p][p]/array[i+1][p];



  for (j=p;j<sloup; j++) {
     array[i+1][j]=array[i+1][j]*cons+array[p][j];


 }


 }

}



array1[n]=array[n-1][n]/array[n-1][n-1];

for (i=n-1; i>=0; i--) {
       cons1=0;

        for (p=n-1;p>=i-1; p--) {

            cons1=cons1+array[i][p]*array1[p];

         }
if (array[i][i]==0 && (array[i][n] - cons1)==0 ) {
 printf("Existuje nekonecne mnoho reseni.\n"); return (EXIT_FAILURE);

}
 else if (array[i][i]==0 && (array[i][n] - cons1)!=0 ) {
   printf("Soustava nema reseni.\n"); return (EXIT_FAILURE);

 }

 else if (array[i][i]==0 && (array[i][n] - cons1)!=0 ) {
      printf("Nespravny vstup.\n"); return (EXIT_FAILURE);

 }

 else {


 array1[i] = (array[i][n] - cons1) / array[i][i];

 }



}


printf("Jedno reseni:\n");

for (i=0; i<=n-1; i++) {

  printf("x%d =  %f  \n", i+1, array1[i]);



}



    return 0;
}