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

using namespace std;

float Jacobi(int n,float A[][4],float B[],float X[]){
int i,j;
float sum,eps=0.001;
float Xn[4],Xn1[4];
int sem;

for(i=1;i<=n;i++){
sum=0;
for(j=1;j<=n;j++) sum=sum+fabs(A[i][j]);
if(sum>2*fabs(A[i][i])) return 1;
}

for(i=1;i<=n;i++)
 Xn[i]=X[i];
do{
sem=0;
for(i=1;i<=n;i++)
 Xn1[i]=Xn[i];
for(i=1;i<=n;i++)
{
Xn[i]=B[i];
for(j=1;j<=n;j++)
  if(j!=i) Xn[i]=Xn[i]-A[i][j]*Xn1[j];
Xn[i]=Xn[i]/A[i][i];
}
for(i=1;i<=n;i++)
if(fabs(Xn[i]-Xn1[i])>eps) sem=1;
}while(sem==1);

for(i=1;i<=n;i++) X[i]=Xn[i];
return 0;}


int main(){
float A[4][4]={{0,-0.9,2,-1},{0,2.1,0.6,3},{0,0,0,0},{0,5,0.5,3}};
float B[4]={0,1,2,3},X[4];
int n=3,i;

if(Jacobi(n,A,B,X)==1) cout<<"eroare"<<endl;
else
{for(i=1;i<=n;i++) cout<<X[i]<<endl;
system("pause");
}
return 0;
}