#include<stdio.h>
#include<windows.h>

void revMatrix(float[][10],int,float[][10]);
void proverka(float[][10],int,float*,float*);

int main() {
  SetConsoleCP(1251);
  SetConsoleOutputCP(1251);

  float A[10][10], x[10], b[10], d[10][10], a=1, T[10][10],k;
  int i, j, n, m, p,l;

  printf("n = ");
  scanf("%d",&n);
  printf("Ìàññèâ A:\n");

  for (i = 0; i < n ; i++)
    for (j = 0 ; j < n ; j++)
      scanf("%f", &A[i][j]);

  printf("Âåêòîð b:\n");
  for ( i = 0 ; i < n ; i++)
    scanf("%f", &b[i]);

  for (l = 0 ; l < n - 1 ; k++)
  	for (i = l + 1 ; i < n ;i++) {
  	  d[i][l] = A[i][l] / A[l][l];
  	  for ( j = 0 ; j < n ; j++)
  	    A[i][j] = A[i][j] - d[i][l] * A[l][j];
  	  b[i] = b[i] - d[i][l] * b[l];
	 }

  printf(" A = \n");
  for ( i = 0 ; i < n ; i++) {
  	for ( j = 0 ; j < n ; j++)
	  printf("%10f",A[i][j]);
	printf("\n");
  }

  printf(" b = \n");
  for ( i = 0 ; i < n ; i++)
    printf("%f\n",b[i]);
  x[n-1] = b[n-1] / A[n-1][n-1];

  for ( i = n - 2 ; i >= 0 ; i--) {
  	k = 0;
    for ( j = i + 1 ; j < n ; j++)
      k += A[i][j] * x[j];
	x[i] = (b[i] - k) / A[i][i];  //ðåøåíèå ñèñòåìû
  }

  printf(" x = \n");
  for ( i = 0 ; i < n ; i++)
    printf("%f\n",x[i]);
	puts("proverka");
//	proverka(A,n,x);
  for ( i = 0 ; i < n; i++)   //íàõîæäåíèå îïðåäåëèòåëÿ
    a *= A[i][i];


  printf( " a = %f\n",a);
  for ( m = 0 ; m < n ; m++) {
  	 for ( p = 0 ; p < n ; p++) {   //îáðàòíàÿ ìàòðèöà
  	   if( p == m )
  	     b[p] = 1;
  	   else
  	     b[p] = 0;
  	 }
  	 for ( l = 0 ; l < n-1 ; k++)
  	   for ( i = l+1 ; i < n ;i++) {
  	     b[i] = b[i] - d[i][l] * b[l];
	   }

     T[n-1][m] = b[n-1] / A[n-1][n-1];
     for ( i = n-2; i >= 0; i--) {
  		k = 0;
     for ( j = i+1 ; j < n ; j++)
      k += A[i][j] * T[j][m];
	  T[i][m] = (b[i]-k) / A[i][i];
     }
  }
  printf("\nproverka\n");
  revMatrix(A,n,T);
  printf("Îáðàòíàÿ ìàòðèöà:\n");
  for ( i = 0 ; i < n ; i++) {
  	for ( j = 0 ; j < n ; j++)
	  printf("%10f",T[i][j]);
	printf("\n");
  }

  return 0;
}