#include <iostream>

#include<stdio.h>

#include<stdlib.h>

#include<math.h>

#include<iomanip>

using namespace std;

double A[3][3];

double Y[3]={1,1,1};

double X[3]={0,0,0};

int row=0; int col=0;

double max1=0;

void open_file()

{

    FILE *fp;

    fp = fopen("array.txt", "r");      //3*3矩阵由外部读入

    if(fp==NULL)

        cout<<"File opened failed!"<<endl;

    for(row=0;row<3;row++)

    {

        for(col= 0; col < 3; col ++)

            fscanf(fp, "%lf,",&A[row][col]);

        if(feof(fp)) break;

    }

    fclose(fp);

}

void mult()

{

    X[0]=0;X[1]=0;X[2]=0;

    for(row=0;row<3;row++)

    {

        for(col=0;col<3;col++)

            X[row] +=A[row][col]*Y[col];

    }

}

void to1()

{

    long double tmp=fabs(X[0]);

    for(int i=1;i<3;i++)

    {

        if(fabs(X[i])>tmp)

            tmp=fabs(X[i]);

    }

    for(int i=0;i<3;i++)

    {

        Y[i]=X[i]/tmp;

    }

    max1=tmp;

}

int main()

{

    cout <<setiosflags(ios::fixed);

    open_file();

    double ago=max1+100.0;

    double feature_vector[3];

    int k=1;

    while(fabs(max1-ago)>0.000001)

    {

          ago=max1;

          for(int j=0;j<3;j++)

          {

              feature_vector[j]=Y[j];

          }

          mult();

          to1();

          cout<<"k= "<<k<<"  ";

          for(int i=0;i<3;i++)

              cout<<X[i]<<" ";

          cout<<endl;

          k++;

    }

    cout<<endl<<"totally run "<<k-1<<" times"<<endl;

    cout<<endl<<"the matrix eigenvalue is "<<max1<<endl;

    cout<<endl<<"the feature vector is "<<"["<<feature_vector[0]<<" , "<<feature_vector[1]<<" , "<<feature_vector[2]<<"]"<<endl;

}