this program runs but not correctly numbers arent right, i read numbers from a file and then when i am using them in the program they are not right.:brief decription of what i am trying to do can someone tell me if something doesnt look right.

this is what i have to do:

write a program that determines the grade dispersal for 100 students

You are to read the exam scores into three arrays, one array for each exam. You must then calculate how many students scored A’s (90 or above), B’s (80 or above), C’s (70 or above), D’s (60 or above), and F’s (less than 60). Do this for each exam and write the distribution to the screen.

    // basic file operations
    #include <iostream>
    #include <fstream>
    using namespace std;
    int read_file_in_array(double exam[100][3]);
    double calculate_total(double exam1[], double exam2[], double exam3[]); // function that calcualates grades to see how many 90,80,70,60
    //void display_totals();
    double exam[100][3];
    int main()
    {
        double go,go2,go3;
        double exam[100][3],exam1[100],exam2[100],exam3[100];
        go=read_file_in_array(exam);
        go2=calculate_total(exam1,exam2,exam3);
        //go3=display_totals();
        cout << go,go2,go3;
        return 0;
    }
    /*
    int display_totals()
    {

        int grade_total;
        grade_total=calculate_total(exam1,exam2,exam3);
        return 0;
    }   */
    double calculate_total(double exam1[],double exam2[],double exam3[])
    {
        int calc_tot,above90=0, above80=0, above70=0, above60=0,i,j, fail=0;
        double exam[100][3];
        calc_tot=read_file_in_array(exam);
        for(i=0;i<100;i++)
            {
            for (j=0; j<3; j++)
                {
                exam1[i]=exam[100][0];
                exam2[i]=exam[100][1];
                exam3[i]=exam[100][2];
                if(exam[i][j] <=90 && exam[i][j] >=100)
                    {
                    above90++;
                        {
                        if(exam[i][j] <=80 && exam[i][j] >=89)
                            {
                            above80++;
                                {
                                if(exam[i][j] <=70 && exam[i][j] >=79)
                                    {
                                    above70++;
                                        {
                                        if(exam[i][j] <=60 && exam[i][j] >=69)
                                            {
                                            above60++;
                                                {
                                                if(exam[i][j] >=59)
                                                    {
                                                    fail++;
                                                }
                                                }
                                        }
                                        }
                                }
                                }
                        }
                        }
                }
            }
        }
        return 0;
    }

    int read_file_in_array(double exam[100][3])
    {
        ifstream infile;  
        int exam1[100];
        int exam2[100];
        int exam3[100];
      infile.open("grades.txt");// file containing numbers in 3 columns
        if(infile.fail()) // checks to see if file opended
            {
            cout << "error" << endl;
            }
        int num, i=0,j=0;
        while(!infile.eof()) // reads file to end of line
          {
              for(i=0;i<100;i++) // array numbers less than 100
              {
                for(j=0;j<3;j++) // while reading get 1st array or element
                infile >> exam[i][j];
                infile >> exam[i][j];
                infile >> exam[i][j];
                cout << exam[i][j] << endl;
                    {
                        if (! (infile >> exam[i][j]) )
                        cout << exam[i][j] << endl;
                    }
              exam[i][j]=exam1[i];
              exam[i][j]=exam2[i];
              exam[i][j]=exam3[i];
              }     
        infile.close();
      }
    return 0;
    }