C Assignments

#include <stdio.h>
#include <stdlib.h>
#define STUDENTS 20
#define ASSIGNMENTS 5

void fillArrayRand(int grades[STUDENTS][ASSIGNMENTS])
{
    for(int i=0;i<STUDENTS;i++){
        for(int j=0;j<ASSIGNMENTS;j++){
            grades[i][j]=rand()%10-1;
        }
    }
}

void fillArray(int grades[STUDENTS][ASSIGNMENTS])
{
    int grade = 0;
    int j;
    for(int i=0;i<STUDENTS;i++){
        j = 0;
        printf("\nStudent %d: Please fill the grades. (type number and press Enter.)\n", i+1);
        while(j != ASSIGNMENTS){
            printf("Please, type:\t");
            scanf("%d", &grade);
            if (grade >= -1 && grade <= 10){
                grades[i][j] = grade;
                printf("\tSuccess! Go on.\n");
                j++;
            }
            else {
                printf("\tGrade not valid! Repeat.\n");
            }

        }
    }
}

void printArray(int grades[STUDENTS][ASSIGNMENTS])
{
    printf("Printing the formatted array ->\n");
    printf("Students\t"); for(int i = 0;i<ASSIGNMENTS;i++) printf("Assignment #%d\t", i+1);
    printf("\n");
    for(int i=0;i<STUDENTS;i++){
        printf("\t%d\t\t", i+1);
        for(int j=0;j<ASSIGNMENTS;j++){
            printf("%d\t\t", grades[i][j]);
        }
        printf("\n");
    }
    printf("===============================\n");
}

void findMax(int grades[STUDENTS][ASSIGNMENTS])
{
    printf("Best grade of each student ->\n");
    int max, pos;
    printf("Students\tBest Grade\tAssignment (*)\n");
    for(int i=0;i<STUDENTS;i++){
        pos = 0;
        printf("\t%d\t", i+1);
        max = -2;
        for(int j=0;j<ASSIGNMENTS;j++){
            if (grades[i][j] > max)
            {
                max = grades[i][j];
                pos = j + 1;
            }
        }
        printf("\t%d\t\t%d\n", max, pos);
    }
    printf("(*The best grade was achieved at this assignment.)\n");
    printf("===============================\n");
}

void findMin(int grades[STUDENTS][ASSIGNMENTS])
{
    printf("Worst grade per assignment ->\n");
    int min, pos;
    printf("Assignments\tWorst Grade\tStudent (*)\n");
    for(int j=0;j<ASSIGNMENTS;j++){
        min = 10;
        pos = 0;
        printf("\t%d\t", j+1);
        for(int i=0;i<STUDENTS;i++){
            if (grades[i][j] <= min && grades[i][j] != -1)
            {
                min = grades[i][j];
                pos = i + 1;
            }
        }
        printf("\t%d\t\t%d\n", min, pos);
    }
    printf("(*The student whose grade was the worst at the specific assignment.)\n");
    printf("===============================\n");
}

void findMean(int grades[STUDENTS][ASSIGNMENTS])
{
    printf("Mean grade of each student ->\n");
    double sum = 0, counter = 0;
    double mean;
    printf("Students\tMean Grade\n");
    for(int i=0;i<STUDENTS;i++){
        printf("\t%d\t", i+1);
        for(int j=0;j<ASSIGNMENTS;j++){
            if (grades[i][j] != -1)
            {
                sum += grades[i][j];
                counter++;
            }
        }
        mean = sum/counter;
        printf("\t%f\n", mean);
    }
    printf("===============================\n");
}

void checkIfEligible(int grades[STUDENTS][ASSIGNMENTS])
{
    int sum, counter;
    printf("Eligibility for the exam ->\n");
    printf("Students\tEligible\tNotes\n");
    for(int i=0;i<STUDENTS;i++){
        sum = 0;
        counter = 0;
        printf("\t%d\t", i+1);
        for(int j=0;j<ASSIGNMENTS;j++){
            if (grades[i][j] != -1)
            {
                sum += grades[i][j];
                counter++;
            }
        }
        (sum >= 25 && counter >=3) ? printf("Yes") : printf("No");
        printf("\t\t(sum of grades = %d, submitted assignments = %d)\n", sum, counter);
        /*if (sum >= 25 && counter >= 3)
        {
            printf("Yes")
        }
        else
        {
        printf("\n");
        }*/
    }
    printf("===============================\n");
}

int main()
{
    int grades[STUDENTS][ASSIGNMENTS];
    fillArrayRand(grades); // γεμίζει τον 2Δ πίνακα με τυχαίους βαθμούς (-1 έως 10)
    printArray(grades); // τυπώνει όμορφα τον πίνακα των βαθμών
    findMax(grades);
    findMin(grades);
    findMean(grades);
    checkIfEligible(grades);
    return 0;
}