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package polynomial;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.text.DecimalFormat;
import java.util.Scanner;

/**
 *
 * @author casey
 */
public class Polynomial {


    public static void main(String[] args) throws FileNotFoundException {

        Scanner read = new Scanner(new BufferedReader(new FileReader("poly.txt")));
        //read.useDelimiter("~|\\n");
        String line = "";
            //first line into x array
            line = read.nextLine();
            System.out.println("LINE: "+line);
            String[] x = line.split("\\s+");
            //second line into y array
            line = read.nextLine();
            System.out.println("LINE: "+line);
            String[] y = line.split("\\s+");

        read.close();

        Double[][] array = new Double[(x.length)*2][y.length+1];

        DecimalFormat df = new DecimalFormat("###.###");
         int a = 0;

        for(int i = 0; i<(x.length*2); i=i+2){

            array[i][0] = Double.parseDouble(x[a]);
            a++;

        }
        a=0;
        for(int j = 0; j<(y.length*2); j=j+2){
            array[j][1] = Double.parseDouble(y[a]);
            a++;

        }


        System.out.println("x\t"+"f[]\t"+"f[,]\t"+"f[,,]\t"+"f[,,,]");
        int j = 0;
        int i = 0;


          for(i = 0; i <=x.length; i=i+2){
            array[i+1][j+2] = ((array[i+2][j+1]) - (array[i][j+1])) /((array[i+2][j]) - (array[i][j]));
          }




            array[i-2][j+3] = ((array[i-1][j+2]) - (array[i-3][j+2])) /((array[i][j]) - (array[i-4][j]));
            array[i-4][j+3] = ((array[i-3][j+2]) - (array[i-5][j+2])) /((array[i-2][j]) - (array[i-6][j]));
            array[i-3][j+4] = ((array[i-2][j+3]) - (array[i-4][j+3])) /((array[i][j]) - (array[i-6][j]));



        for(int s = 0; s<x.length*2; s++){
            for(int t = 0; t<y.length+1; t++){
                //System.out.println("Piece: "+df.format(array[0][0]));
                 System.out.print((array[s][t])+"\t");
            }
            System.out.println();
        }
        //3 + (1/2)(x-1) +  (1/3)(x-1)(x-3/2) - 2(x-1)(x-3/2)x
        String polynomial = array[0][1]+"+"+array[1][2]+"(x-"+array[0][0]+")+"+df.format(array[2][3])+"(x-"+(array[0][0])+")"+"(x-"+(array[2][0])+")+"
                +df.format(array[3][4])+"(x-"+array[4][0]+")(x-"+(array[0][0]+")"+"(x-"+(array[2][0])+")");
        System.out.println("Interloping Polynomial is: "+polynomial);
    }



}