I am getting the error message below when I try to make my source code file.

gcc -o grading.c -lm

/usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/crt1.o: In function `_start':

(.text+0x20): undefined reference to `main'

collect2: ld returned 1 exit status

make: *** [grading] Error 1

the source code \/insert

Code:/* ******************************************************** *** *** */ #include <stdio.h> #include <stdlib.h> int main () { /* main */ /* *************************** *** Declaration Section *** *************************** * ***************************** * Named Constant Subsection * ***************************** * * A_grade the minimum grade a student needs to get an A. * B_grade the minimum grade a student needs to get a B. * C_grade the minimum grade a student needs to get a C. * D_grade the minimum grade a student needs to get a D. * F_grade the minimum grade a student needs to get an F. * initial_sum initial sum that various things are set to. * max_pos_scr the max score possible in the class. * spring value used to represent the spring semester. * fall value used to represent the fall semester. * program_failure_code used to exit the program due to idiotproofing. * quiz_one_points the max points available for quiz one. * quiz_two_points the max points available for quiz two. * quiz3_points the max points available for quiz three. * quiz_four_points the max points available for quiz four. * pp1_points the maximum number of points available for pp1 * pp2_points the maximum number of points available for pp2 * pp3_points the maximum number of points available for pp3 * lab_points the max pts available for labs. * final_exam_points the max pts available for the final exam. * first_student number representing the 1st value in an array */ const float A_grade = 4500; const float B_grade = 4000; const float C_grade = 3500; const float D_grade = 3000; const float F_grade = 0; const float initial_sum = 0; const float max_pos_scr = 5000.0; const int spring = 1; const int fall = 2; const int program_failure_code = -1; const int quiz_one_points = 30; const int quiz_two_points = 170; const int quiz3_points = 130; const int quiz_four_points = 115; const int pp1_points = 250; const int pp2_points = 1000; const int pp3_points = 2000; const int lab_points = 505; const int final_exam_points = 800; const int first_student = 0; const int zero = 0; const int one = 1; /* ***************************** * Local Variable Subsection * ***************************** * * quiz_one_score array that holds the scores for quiz one. * quiz_two_score array that holds the scores for quiz two. * quiz3_score array that holds the scores for quiz three * quiz_four_score array that holds the scores for quiz four. * pp1_score an array that holds the scores for pp1. * pp2_score an array that holds the scores for pp2. * pp3_score an array that holds the scores for pp3. * lab_score array holding the lab scores * fnl_exm_scr array holding the final exam scores * overall_score array holding the overall scores * stdt_prcntg_scr_score array holding overall percentage scores * student_ID an array that holds the student ID's. * student_letter_grade array holding student letter grades. * overall_score_sum sum of the overall scores of all students. * overall_score_mean mean of the overall scores of all students * quiz_one_score_sum sum of the quiz one scores of all students * quiz_one_score_mean mean quiz one scores of all students. * quiz_two_score_sum sum of the quiz two scores * quiz_two_score_mean mean quiz two scores * quiz3_score_sum sum of the quiz three scores * quiz3_score_mean mean quiz three scores * quiz_four_score_sum sum of quiz four scores. * quiz_four_score_mean mean quiz four scores of all students. * pp1_score_sum sum of the pp1 scores of all students. * pp1_score_mean mean of the pp1 scores of all students. * pp2_score_sum sum of the pp2 scores of all students. * pp2_score_mean mean of the pp2 scores of all students. * pp3_score_sum sum of the pp3 scores of all students. * pp3_score_mean mean of the pp3 scores of all students. * lab_score_sum sum of the lab scores of all students. * lab_score_mean mean of the lab scores of all students. * fnl_exm_scr_sum sum of final exam scores of all students. * fnl_exm_scr_mean mean final exam scores of all students. * quiz1_lowest_score the lowest quiz one score. * quiz2_lowest_score the lowest quiz two score. * quiz3_lowest_score the lowest quiz three score. * quiz4_lowest_score the lowest quiz four score. * pp1_lowest_score the lowest pp1 score. * pp2_lowest_score the lowest pp2 score. * pp3_lowest_score the lowest pp3 score. * lab_lowest_score the lowest lab score. * final_exam_lowest_score the lowest final exam score. * quiz1_highest_score the highest quiz one score. * quiz2_highest_score the highest quiz two score. * quiz3_highest_score the highest quiz three score. * quiz4_highest_score the highest quiz four score. * pp1_highest_score the highest pp1 score. * pp2_highest_score the highest pp2 score. * pp3_highest_score the highest pp3 score. * lab_highest_score the highest lab score. * final_exam_highest_score the highest final exam score. * stdt_prcntg_scr_sum sum of overall percentage scores. * stdt_prcntg_scr_mean mean overall percentage scores. * low_overall_percentage_score the lowest overall percentage score. * high_overall_percentage_score the highest overall percentage score. * year reps the year the student was enrolled. * semester reps the fall or spring semester. * num_students num students enrolled in the class. * student reps the position in an array of students. * num_As num who received an A in the class. * num_Bs num who received a B in the class. * num_Cs num who received a C in the class. * num_Ds num who received a D in the class. * num_Fs num who received an F in the class. * */ float* quiz_one_score = (float*)NULL; float* quiz_two_score = (float*)NULL; float* quiz3_score = (float*)NULL; float* quiz_four_score = (float*)NULL; float* pp1_score = (float*)NULL; float* pp2_score = (float*)NULL; float* pp3_score = (float*)NULL; float* lab_score = (float*)NULL; float* fnl_exm_scr = (float*)NULL; float* overall_score = (float*)NULL; float* stdt_prcntg_scr = (float*)NULL; int* student_ID = (int*)NULL; char* student_letter_grade = (char*)NULL; float overall_score_sum; float overall_score_mean; float quiz_one_score_sum; float quiz_one_score_mean; float quiz_two_score_sum; float quiz_two_score_mean; float quiz3_score_sum; float quiz3_score_mean; float quiz_four_score_sum; float quiz_four_score_mean; float pp1_score_sum; float pp1_score_mean; float pp2_score_sum; float pp2_score_mean; float pp3_score_sum; float pp3_score_mean; float pp4_score_sum; float pp4_score_mean; float lab_score_sum; float lab_score_mean; float fnl_exm_scr_sum; float fnl_exm_scr_mean; float quiz1_lowest_score; float quiz2_lowest_score; float quiz3_lowest_score; float quiz4_lowest_score; float pp1_lowest_score; float pp2_lowest_score; float pp3_lowest_score; float lab_lowest_score; float final_exam_lowest_score; float quiz1_highest_score; float quiz2_highest_score; float quiz3_highest_score; float quiz4_highest_score; float pp1_highest_score; float pp2_highest_score; float pp3_highest_score; float lab_highest_score; float final_exam_highest_score; float stdt_prcntg_scr_sum; float stdt_prcntg_scr_mean; float low_overall_percentage_score; float high_overall_percentage_score; int year; int semester; int num_students; int student; int num_As; int num_Bs; int num_Cs; int num_Ds; int num_Fs; /* ************************* *** Execution Section *** ************************* * /* ************************ *** Input Subsection *** ************************ * */ /* * Input the year and semester (1 for spring, 2 for fall). */ scanf("%d %d", &year, &semester); /* * Idiot-proof the input for the year and semester. */ if (year < zero) { /* * Output the error message and exit */ printf("ERROR: unknown year and semester code %d.\n", semester); exit(program_failure_code); } /* * Input the number of students enrolled in the class. */ scanf("%d", &num_students); /* * Idiot-proof the input for the number of students enrolled. */ if (num_students < one) { /* * Output the error message and exit */ printf("ERROR: unknown num students code %d.\n", num_students); exit(program_failure_code); } /* * Allocate and Idiotproof each array. */ student_ID = (int*)malloc(sizeof(int)*num_students); if (student_ID == (int*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" student ID failed.\n"); exit(program_failure_code); } /* if (student_ID == (int*)NULL */ quiz_one_score = (float*)malloc(sizeof(float)*num_students); if (quiz_one_score == (float*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" quiz one score failed.\n"); exit(program_failure_code); } /* if (quiz_one_score == (float*)NULL */ quiz_two_score = (float*)malloc(sizeof(float)*num_students); if (quiz_two_score == (float*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" quiz two score failed.\n"); exit(program_failure_code); } /* if (quiz_two_score == (float*)NULL */ quiz3_score = (float*)malloc(sizeof(float)*num_students); if (quiz3_score == (float*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" quiz three score failed.\n"); exit(program_failure_code); } /* if (quiz3_score == (float*)NULL */ quiz_four_score = (float*)malloc(sizeof(float)*num_students); if (quiz_four_score == (float*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" quiz four score failed.\n"); exit(program_failure_code); } /* if (quiz_four_score == (float*)NULL */ pp1_score = (float*)malloc(sizeof(float)*num_students); if (pp1_score == (float*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" pp1 score failed.\n"); exit(program_failure_code); } /* if (pp1_score == (float*)NULL */ pp2_score = (float*)malloc(sizeof(float)*num_students); if (pp2_score == (float*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" pp2 score failed.\n"); exit(program_failure_code); } /* if (pp2_score == (float*)NULL */ pp3_score = (float*)malloc(sizeof(float)*num_students); if (quiz_one_score == (float*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" pp3 score failed.\n"); exit(program_failure_code); } /* if (pp3_score == (float*)NULL */ lab_score_score = (float*)malloc(sizeof(float)*num_students); if (lab_score == (float*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" lab score failed.\n"); exit(program_failure_code); } /* if (lab_score == (float*)NULL */ fnl_exm_scr_score = (float*)malloc(sizeof(float)*num_students); if (fnl_exm_scr_score == (float*)NULL { printf("ERROR: the attempt to allocate\n"); printf(" final exam score failed.\n"); exit(program_failure_code); } /* if (fnl_exm_scr_score == (float*)NULL */ student_letter_grade = (char*)malloc(sizeof(char)*num_students); if (student_letter_grade == (char*)NULL) { printf("ERROR: the attempt to allocate\n"); printf(" the student's letter grade failed.\n"); exit(program_failure_code); } /* if (student_letter_grade == (char*)NULL) */ stdt_prcntg_scr = (float*)malloc(sizeof(float)*num_students); if (stdt_prcntg_scr == (float*)NULL) { printf("ERROR: the attempt to allocate\n"); printf(" the student's overall percentage score failed.\n"); exit(program_failure_code); } /* if (stdt_prcntg_scr == (float*)NULL) */ /* * make a for loop that will read all the information for each student */ for (student = first_student; student < num_students; student++) { /* * Input each of the elements from the database into each array. */ scanf("%d %f %f %f %f %f %f %f %f %f", &student_ID[student], &quiz_one_score[student], &quiz_two_score[student], &quiz3_score[student], &quiz_four_score[student], &pp1_score[student], &pp2_score[student], &pp3_score[student], &lab_score[student], &fnl_exm_scr[student]); printf("Done inputting data for student #%d:\n", student); printf("student_ID[%d]: %f\n", student, student_ID[student]); printf("quiz_one_score[%d]: %f\n", student, quiz_one_score[student]); printf("quiz_two_score[%d]: %f\n", student, quiz_two_score[student]); printf("quiz3_score[%d]: %f\n", student, quiz3_score[student]); printf("quiz_four_score[%d]: %f\n", student, quiz_four_score[student]); printf("pp1_score[%d]: %f\n", student, pp1_score[student]); printf("pp2_score[%d]: %f\n", student, pp2_score[student]); printf("pp3_score[%d]: %f\n", student, pp3_score[student]); printf("fnl_exm_scr[%d]: %f\n", student, fnl_exm_scr[student]); } /* for student */ /* insert idiotproofing here */ /* ****************************** *** Calculation Subsection *** ****************************** */ /* Calculate each students overall score, overall percentage *score for the semester and their letter grade*/ for (student = first_student; student<num_students; student++) { overall_score[student] = quiz_one_score[student] + quiz_two_score[student] + quiz3_score[student] + quiz_four_score[student] + pp1_score[student] + pp2_score[student] + pp3_score[student] + lab_score[student] + fnl_exm_scr[student]; stdt_prcntg_scr[student] = overall_score[student]/max_pos_scr; if (overall_score >= A_grade) { student_letter_grade[student] = A; } /* if (overall_score >= A_grade) */ else if (overall_score >= B_grade) { student_letter_grade[student] = B; } /* if (overall_score >= B_grade) */ else if (overall_score >= C_grade) { student_letter_grade[student] = C; } /* if (overall_score >= C_grade) */ else if (overall_score >= D_grade) { student_letter_grade[student] = D; } /* if (overall_score >= D_grade) */ else if (overall_score >= F_grade) { student_letter_grade[student] = F; } /* if (overall_score >= F_grade) */ } /* calculate the score means by first adding up all the scores*/ overall_score_sum = initial_sum; quiz_one_score_sum = initial_sum; quiz_two_score_sum = initial_sum; quiz3_score_sum = initial_sum; quiz_four_score_sum = initial_sum; pp1_score_sum = initial_sum; pp2_score_sum = initial_sum; pp3_score_sum = initial_sum; lab_score_sum = initial_sum; fnl_exm_scr_sum = initial_sum; for (student = first_student; student < num_students; student++) { /* calculate the sum of the overall scores */ overall_score_sum += overall_score[student]; /* calculate the sum of the mean scores for quiz one */ quiz_one_score_sum += quiz_one_score[student]; /* calculate the sum of the mean scores for quiz two */ quiz_two_score_sum += quiz_two_score[student]; /* calculate the sum of the mean scores for quiz three */ quiz3_score_sum += quiz3_score[student]; /* calculate the sum of the mean scores for quiz four */ quiz_four_score_sum += quiz_four_score[student]; /* calculate the sum of the mean scores for pp1 */ pp1_score_sum += pp1_score[student]; /* calculate the sum of the mean scores for pp2 */ pp2_score_sum += pp2_score[student]; /* calculate the sum of the mean scores for pp3 */ pp3_score_sum += pp3_score[student]; /* calculate the sum of the mean scores for the labs */ lab_score_sum += lab_score[student]; /* calculate the sum of the mean scores for the final exams */ fnl_exm_scr_sum += fnl_exm_scr[student]; } /* calculate the mean score for all the students overall. */ overall_score_mean = overall_score_sum/num_students; /* calculate the mean score for quiz one. */ quiz_one_score_mean = quiz_one_score_sum/num_students; /* calculate the mean score for quiz two. */ quiz_two_score_mean = quiz_two_score_sum/num_students; /* calculate the mean score for quiz three. */ quiz3_score_mean = quiz3_score_sum/num_students; /* calculate the mean score for quiz four. */ quiz_four_score_mean = quiz_four_score_sum/num_students; /* calculate the mean score for pp1. */ pp1_score_mean = pp1_score_sum/num_students; /* calculate the mean score for pp2. */ pp2_score_mean = pp2_score_sum/num_students; /* calculate the mean score for pp3. */ pp3_score_mean = pp3_score_sum/num_students; /* calculate the mean score for lab. */ lab_score_mean = lab_score_sum/num_students; /* calculate the mean score for the final exam. */ fnl_exm_scr_mean = fnl_exm_scr_sum/num_students; /* * Calculate the lowest quiz one score score of all the students. */ quiz1_lowest_score = quiz_one_score[first_student]; for (student = first_student; student < num_students; student++) { if (quiz_one_score[student] < quiz1_lowest_score) { quiz1_lowest_score = quiz_one_score[student]; } /* if (quiz_one_score[student] < quiz1_lowest_score) */ } /* for student */ /* * Calculate the lowest quiz two score score of all the students. */ quiz2_lowest_score = quiz_two_score[first_student]; for (student = first_student; student < num_students; student++) { if (quiz_two_score[student] < quiz2_lowest_score) { quiz2_lowest_score = quiz_two_score[student]; } /* if (quiz_two_score[student] < quiz2_lowest_score) */ } /* for student */ /* * Calculate the lowest quiz three score score of all the students. */ quiz3_lowest_score = quiz3_score[first_student]; for (student = first_student; student < num_students; student++) { if (quiz3_score[student] < quiz3_lowest_score) { quiz3_lowest_score = quiz3_score[student]; } /* if (quiz3_score[student] < quiz3_lowest_score) */ } /* for student */ /* * Calculate the lowest pp1 score score of all the students. */ pp1_lowest_score = pp1_score[first_student]; for (student = first_student; student < num_students; student++) { if (pp1_score[student] < pp1_lowest_score) { pp1_lowest_score = pp1_score[student]; } /* if (pp1_score[student] < pp1_lowest_score) */ } /* for student */ /* * Calculate the lowest pp2 score score of all the students. */ pp2_lowest_score = pp2_score[first_student]; for (student = first_student; student < num_students; student++) { if (pp2_score[student] < pp2_lowest_score) { pp2_lowest_score = pp2_score[student]; } /* if (pp2_score[student] < pp2_lowest_score) */ } /* for student */ /* * Calculate the lowest pp3 score score of all the students. */ pp3_lowest_score = pp3_score[first_student]; for (student = first_student; student < num_students; student++) { if (pp3_score[student] < pp3_lowest_score) { pp3_lowest_score = pp3_score[student]; } /* if (pp3_score[student] < pp3_lowest_score) */ } /* for student */ /* * Calculate the lowest lab score score of all the students. */ lab_lowest_score = quiz_one_score[first_student]; for (student = first_student; student < num_students; student++) { if (lab_score[student] < lab_lowest_score) { lab_score = lab_score[student]; } /* if (lab_score[student] < lab_score) */ } /* for student */ /* * Calculate the lowest final exam score score of all the students. */ fnl_exm_scr = fnl_exm_scr[first_student]; for (student = first_student; student < num_students; student++) { if (fnl_exm_scr[student] < final_exam_lowest_score) { final_exam_lowest_score = fnl_exm_scr[student]; } /* if (fnl_exm_scr[student] < final_exam_lowest_score) */ } /* for student */ /* * Calculate the highest quiz one score score of all the students. */ quiz1_highest_score = quiz_one_score[first_student]; for (student = first_student; student < num_students; student++) { if (quiz_one_score[student] > quiz1_highest_score) { quiz1_highest_score = quiz_one_score[student]; } /* if (quiz_one_score[student] > quiz1_highest_score) */ } /* for student */ quiz2_highest_score = quiz_two_score[first_student]; for (student = first_student; student < num_students; student++) { if (quiz_two_score[student] > quiz2_highest_score) { quiz2_highest_score = quiz_two_score[student]; } /* if (quiz_two_score[student] > quiz2_highest_score) */ } /* for student */ quiz3_highest_score = quiz3_score[first_student]; for (student = first_student; student < num_students; student++) { if (quiz3_score[student] > quiz3_highest_score) { quiz3_highest_score = quiz3_score[student]; } /* if (quiz3_score[student] > quiz3_highest_score) */ } /* for student */ quiz4_highest_score = quiz_four_score[first_student]; for (student = first_student; student < num_students; student++) { if (quiz_four_score[student] > quiz4_highest_score) { quiz4_highest_score = quiz_four_score[student]; } /* if (quiz_four_score[student] > quiz4_highest_score) */ } /* for student */ pp1_highest_score = pp1_score[first_student]; for (student = first_student; student < num_students; student++) { if (pp1_score[student] > pp1_highest_score) { pp1_highest_score = pp1_score[student]; } /* if (pp1_score[student] > pp1_highest_score) */ } /* for student */ pp2_highest_score = pp2_score[first_student]; for (student = first_student; student < num_students; student++) { if (pp2_score[student] > pp2_highest_score) { pp2_highest_score = pp2_score[student]; } /* if (pp2_score[student] > pp2_highest_score) */ } /* for student */ pp3_highest_score = pp3_score[first_student]; for (student = first_student; student < num_students; student++) { if (pp3_score[student] > pp3_highest_score) { pp3_highest_score = pp3_score[student]; } /* if (pp3_score[student] > pp3_highest_score) */ } /* for student */ lab_highest_score = lab_score[first_student]; for (student = first_student; student < num_students; student++) { if (lab_score[student] > lab_highest_score) { lab_highest_score = lab_score[student]; } /* if (lab_score[student] > lab_highest_score) */ } /* for student */ final_exam_highest_score = fnl_exm_scr[first_student]; for (student = first_student; student < num_students; student++) { if (fnl_exm_scr[student] > final_exam_highest_score) { final_exam_highest_score = fnl_exm_scr[student]; } /* if (fnl_exm_scr[student] > final_exam_highest_score) */ } /* for student */ /* * Calculate the number of students who received an A. */ for (student = first_student; student < num_students; student++) { if (overall_score[student] >= A_grade) { num_As++; } /* if (overall_score[student] >= A_grade) */ } /* for student */ /* * Calculate the number of students who received a B. */ for (student = first_student; student < num_students; student++) { if (overall_score[student] >= B_grade) { num_Bs++; } /* if (overall_score[student] >= B_grade) */ } /* for student */ /* * Calculate the number of students who received a C. */ for (student = first_student; student < num_students; student++) { if (overall_score[student] >= C_grade) { num_Cs++; } /* if (overall_score[student] >= C_grade) */ } /* for student */ /* * Calculate the number of students who received a D. */ for (student = first_student; student < num_students; student++) { if (overall_score[student] >= D_grade) { num_Ds++; } /* if (overall_score[student] >= D_grade) */ } /* for student */ /* * Calculate the number of students who received an F. */ for (student = first_student; student < num_students; student++) { if (overall_score[student] >= F_grade) { num_Fs++; } /* if (overall_score[student] >= F_grade) */ } /* for student */ /* * Calculate the mean overall percentage score of all students in the course */ for (student = first_student; student<num_students; student++) { stdt_prcntg_scr_sum += stdt_prcntg_scr[student]; } /* for student */ stdt_prcntg_scr_mean = stdt_prcntg_scr_sum/num_students; /* * Calculate lowest overall percentage score of students in the course. */ low_overall_percentage_score = stdt_prcntg_scr[first_student]; for (student = first_student; student < num_students; student++) { if (stdt_prcntg_scr[student] < low_overall_percentage_score) { low_overall_percentage_score = stdt_prcntg_scr[student]; } /* if (stdt_prcntg_scr[student] < low_overall_percentage_score) */ } /* for student */ /* * Calculate highest overall percentage score of students in the course. */ high_overall_percentage_score = stdt_prcntg_scr[first_student]; for (student = first_student; student < num_students; student++) { if (stdt_prcntg_scr[student] > high_overall_percentage_score) { high_overall_percentage_score = stdt_prcntg_scr[student]; } /* if (stdt_prcntg_scr[student] > high_overall_percentage_score) */ } /* for student */ /* ************************* *** Output Subsection *** ************************* */ /* * output the name of the course, the semester, the year, in that order * output the number of students. * output each of the items that were calculated, * in the same order as the calculation subsection */ free(fnl_exm_scr); fnl_exm_scr = (float*)NULL; free(lab_score); lab_score = (float*)NULL; free(pp3_score); pp3_score = (float*)NULL; free(pp2_score); pp2_score = (float*)NULL; free(pp1_score); pp1_score = (float*)NULL; free(quiz_four_score); quiz_four_score = (float*)NULL; free(quiz3_score); quiz3_score = (float*)NULL; free(quiz_two_score); quiz_two_score = (float*)NULL; free(quiz_one_score); quiz_one_score = (float*)NULL; free(student_ID); student_ID = (int*)NULL; } /* main */