#include <stdio.h>


#define sqr(x) ((x)*(x))
#define max(a,b) (((a)>(b))?(a):(b))


double computeQuizGrade (int grades[5])

{ double worst, floats[5];  int n;

  // normalize grades
  floats[0] = grades[0]/30.0;
  floats[1] = grades[1]/20.0;
  floats[2] = grades[2]/30.0;
  floats[3] = grades[3]/20.0;
  floats[4] = grades[4]/30.0;

  // drop worst normalized grade
  worst = floats[0];
  for (n=1; n<5; n++)
    if (worst > floats[n]) worst = floats[n];
  for (n=0; n<5; n++)
    if (floats[n] == worst)
      { floats[n] = floats[4]; floats[4] = worst; break; };
  // now floats[0..3] contains the best 4 grades.

  // return average normalized grade with worst dropped
  return (floats[0]+floats[1]+floats[2]+floats[3])/4;
}


double computeMPsGrade (int grades[5])

{ double floats[5];

  // normalize grades
  floats[0] = grades[0]/24.0; 
  floats[1] = grades[1]/30.0;
  floats[2] = grades[2]/30.0;
  floats[3] = grades[3]/30.0;
  floats[4] = grades[4]/20.0;

  return 0.05*floats[0] + 0.3*floats[1] + 0.3*floats[2]
         + 0.3*floats[3] + 0.05*floats[4];
}


int main (void)

{ int plus[45], mp[45][5], quiz[45][5], final[45]; // raw data
  char firstname[45][20], lastname[45][20], id[45][5];
  FILE *fhandle;
  int n;
  // stats
  int countAboveThreshold, l, m, printed[45];
  float quizzes[45], mean, var, machineProblems[45], courseGrade[45], wavg,
    current_max;

  // open raw grades file
  fhandle = fopen ("grades-inputposted.txt", "r");
  if (fhandle == NULL)
    { printf ("Could not open grades file... exiting.\n"); exit (1); };

  // for each record
  for (n=0; n<45; n++) // 45 people who took the class
    {
      // read it in
      fscanf (fhandle, "%s %s %s %d %d %d %d %d %d %d %d %d %d %d %d\n",
        firstname[n], lastname[n], id[n], plus+n,
        mp[n], mp[n]+1, mp[n]+2, mp[n]+3, mp[n]+4,
        quiz[n]+0, quiz[n]+1, quiz[n]+2, quiz[n]+3, quiz[n]+4,
        final+n);

      // compute grades
      quizzes[n] = computeQuizGrade (quiz[n]);
      machineProblems[n] = computeMPsGrade (mp[n]);
      wavg = 0.1*quizzes[n] + 0.55*machineProblems[n] + 0.35*final[n]/100.0;
      courseGrade[n] =  (quizzes[n] > 0.6667)? max(wavg,final[n]/100.0) : wavg;
    };

  // print record
  memset (printed, 0, sizeof(printed));
  for (n=0; n<45; n++)
    { current_max = -1;
      for (l=0; l<45; l++)
        if (!printed[l] && courseGrade[l] > current_max)
          { current_max = courseGrade[l]; m = l; };
      printf ("%2d %2d %2d %2d %2d %2d %2d %2d %2d %2d %2d -- %.4f %.4f | %.2f %c |    | %4s %s %s\n",
        mp[m][0], mp[m][1], mp[m][2], mp[m][3], mp[m][4],
        quiz[m][0], quiz[m][1], quiz[m][2], quiz[m][3], quiz[m][4],
        final[m],
        quizzes[m], machineProblems[m], courseGrade[m],
        plus[m]?'+':'.', id[m], firstname[m], lastname[m]);
      printed[m] = 1;
    };
  printf ("\n");

  // Quiz statistics
  mean = 0; for (n=0; n<45; n++) mean += quizzes[n]; mean /= 45;
  var = 0; for (n=0; n<45; n++) var += sqr(quizzes[n]-mean); var /= 45;
  printf ("Quiz stats -- mean: %.2f, stdev: %.2f.\n", mean, sqrt(var));
  countAboveThreshold = 0;
  for (n=0; n<45; n++) if (quizzes[n] > 0.6667) countAboveThreshold += 1;
  printf ("(# of people above the 2/3 threshold for quizzes: %d, out of 45).\n",
    countAboveThreshold);

  // MPs statistics
  mean = 0; for (n=0; n<45; n++) mean += machineProblems[n]; mean /= 45;
  var = 0; for (n=0; n<45; n++) var += sqr(machineProblems[n]-mean); var /= 45;
  printf ("MPs stats -- mean: %.2f, stdev: %.2f.\n", mean, sqrt(var));

  // Final statistics
  mean = 0; for (n=0; n<45; n++) mean += final[n]; mean /= 45;
  var = 0; for (n=0; n<45; n++) var += sqr(final[n]-mean); var /= 45;
  printf ("Final stats -- mean: %.2f, stdev: %.2f.\n", mean, sqrt(var));

  fclose (fhandle);
  exit (0);
}

// MP1 (24 points) MP2 (30 points) MP3 (30 points) MP4 (30 points) MP5 (20 points) Quiz 1 (30 points) Quiz 2 (20 points) Quiz 3 (30 points) Quiz 4 (20 points) Quiz 5 (30 points) Final Exam (100 points)