Question

Write a program in C to grade an n-question multiple-choice exam (for n between 5 and 20) and provide feedback about the most frequently missed questions. Your program will use a function scan_exam_data to scan and store the exam data in an appropriate data structurer. Use file redirection to input data – do not use fopen() in your code. The first line of input contains the number of students. Second line is number of questions on the exam followed by a space and then an n-character string of the correct answers. Each of the lines that follow contain an integer student ID followed by a space and then the student answers.

Sample Input

3

5 dbbac

111 dabac

102 dcbdc

251 dbbac

Your program then uses a function analyze_data to calculate each student’s score as a percentage and the number of each missed questions in the exam. A function print_data will be called to produce an output, containing the answer key, each student’s ID, each student’s score as a percentage, and information about how many students missed each question.

Sample Output

Exam Report

Students 3

Question 1 2 3 4 5

Answer d b b a c

ID Score(%)

111 80

102 60

251 100

Question 1 2 3 4 5

Missed by 0 2 0 1 0

Error checking
You will have to perform some error checks while the program is being running. However, these error checks will not cause the program to terminate – except if you have a corrupted file. Your program should print error messages when appropriate. Here is a list that need to be checked: Illegal inputs like the number of questions must be between 5-20 and key answers must be lower-case letters.

Answer 1

If you have any doubts, please give me comment...

#include<stdio.h>

void scan_exam_data(int stud_ids[], char stud_answers[][20], int no_students);

void analyze_data(char correct_ans[], char stud_answers[][20], int no_students, int no_questions, int perc[], int misses[]);

void print_data(int stu_ids[], char correct_ans[], int no_studs, int no_ques, int perc[], int misses[]);

int main(){

    int no_students, no_questions, i;

    char correct_answers[21];

    scanf("%d", &no_students);

    scanf("%d %s", &no_questions, correct_answers);

    int stud_ids[no_students];

    char stud_answers[no_students][no_questions+1];

    int percentage[no_students];

    int misses[no_questions];

    for(i=0; i<no_students; i++)

        stud_ids[i] = 0;

    for(i=0; i<no_questions; i++)

        misses[i] = 0;

    scan_exam_data(stud_ids, stud_answers, no_students);

    analyze_data(correct_answers, stud_answers, no_students, no_questions, percentage, misses);

    print_data(stud_ids, correct_answers, no_students, no_questions, percentage, misses);

    return 0;

}

void scan_exam_data(int stud_ids[], char stud_answers[][20], int no_students){

    int i;

    for(i=0; i<no_students; i++){

        scanf("%d %s", &stud_ids[i], stud_answers[i]);

    }

}

void analyze_data(char correct_ans[], char stud_answers[][20], int no_students, int no_questions, int perc[], int misses[]){

    int i, j;

    for(i=0; i<no_students; i++){

        int correct = 0;

        for(j=0; j<no_questions; j++){

            if(correct_ans[j]==stud_answers[i][j])

                correct++;

            else

                misses[j]++;

        }

        perc[i] = ((double)correct/no_questions)*100;

    }

}

void print_data(int stu_ids[], char correct_ans[], int no_studs, int no_ques, int perc[], int misses[]){

    int i;

    printf("Exam Report\n");

    printf("Students %d\n", no_studs);

    printf("Question");

    for(i=1; i<=no_ques; i++)

        printf(" %d", i);

    printf("\nAnswer");

    for(i=0; i<no_ques; i++)

        printf(" %c", correct_ans[i]);

    printf("\n\nID\tScore(%%)\n");

    for(i=0; i<no_studs; i++){

        printf("%d %d\n", stu_ids[i], perc[i]);

    }

    printf("\nQuestion");

    for(i=1; i<=no_ques; i++)

        printf(" %d", i);

    printf("\nMissed by");

    for(i=0; i<no_ques; i++)

        printf(" %d", misses[i]);

    printf("\n");

}