Job Scheduling with Deadlines in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the Job structure with id and deadline fields.

DSA C

typedef struct Job {
    int id;
    int [1];
} Job;

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Apriority

Bduration

Cdeadline

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'priority' instead of 'deadline' for the deadline field.

Confusing 'duration' with deadline.

The field to store the deadline of a job is named deadline.

2fill in blank

medium

Complete the code to sort jobs by their deadline in ascending order.

DSA C

int compareJobs(const void *a, const void *b) {
    Job *jobA = (Job *)a;
    Job *jobB = (Job *)b;
    return jobA->[1] - jobB->[1];
}

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Aduration

Bdeadline

Cpriority

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Sorting by id instead of deadline.

Using priority or duration which are not relevant here.

Sorting by deadline ensures jobs with earlier deadlines come first.

3fill in blank

hard

Fix the error in the code to schedule jobs within their deadlines using a greedy approach.

DSA C

int scheduleJobs(Job jobs[], int result[], int n) {
    int slot[n];
    for (int i = 0; i < n; i++)
        slot[i] = 0;

    for (int i = 0; i < n; i++) {
        for (int j = jobs[i].deadline - 1; j >= 0; j--) {
            if (slot[j] == [1]) {
                result[j] = i;
                slot[j] = 1;
                break;
            }
        }
    }
    return 0;
}

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A0

B1

C-1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Checking if slot[j] == 1 which means occupied, so no assignment happens.

Using negative or invalid values for slot check.

The slot array uses 0 to indicate a free slot and 1 for occupied. We check if slot[j] == 0 to find a free slot.

4fill in blank

hard

Fill both blanks to print the scheduled jobs in order.

DSA C

void printSchedule(Job jobs[], int result[], int n) {
    printf("Scheduled jobs: ");
    for (int i = 0; i < n; i++) {
        if (result[i] != [1]) {
            printf("%d ", jobs[result[i]].[2]);
        }
    }
    printf("\n");
}

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A-1

B0

Cid

Ddeadline

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for 0 instead of -1 in result array.

Printing deadline instead of job id.

We check if result[i] is not -1 (meaning a job is scheduled) and print the job's id.

5fill in blank

hard

Fill all three blanks to initialize the result array with -1 and sort jobs by deadline.

DSA C

void initializeAndSort(Job jobs[], int n, int result[]) {
    for (int i = 0; i < n; i++) {
        result[i] = [1];
    }
    qsort(jobs, n, sizeof(Job), [2]);
}

int compareByDeadline(const void *a, const void *b) {
    Job *jobA = (Job *)a;
    Job *jobB = (Job *)b;
    return jobA->[3] - jobB->[3];
}

Drag options to blanks, or click blank then click option'

A-1

BcompareByDeadline

Cdeadline

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing result with 0 instead of -1.

Using wrong compare function name in qsort.

Comparing by id instead of deadline.

We initialize result with -1 to mark empty slots, use compareByDeadline for sorting, and compare the deadline field.