Activity Selection Problem in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the array that stores the finish times of activities.

DSA C

int finish[] = {1, 3, 6, 5, 8, 9};
int start[] = {0, 1, 3, 4, 6, 8};
int n = sizeof(finish)/sizeof(finish[0]);

// The array to store finish times is called [1];

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

Astart

Bfinish

Cactivities

Dtimes

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing start times with finish times.

Using an undefined variable name.

The array that stores the finish times is named 'finish'.

2fill in blank

medium

Complete the code to select the first activity by initializing the index.

DSA C

int i = 0; // Select the first activity
int count = 1; // Count of selected activities

for (int j = 1; j < n; j++) {
    if (start[j] >= finish[[1]]) {
        i = j;
        count++;
    }
}

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

An

Bcount

Cj

Di

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'j' instead of 'i' to check finish time.

Comparing with 'count' or 'n' which are not indices.

We compare the start time of the current activity with the finish time of the last selected activity, which is at index 'i'.

3fill in blank

hard

Fix the error in the loop condition to correctly iterate over all activities.

DSA C

for (int j = 1; j [1] n; j++) {
    if (start[j] >= finish[i]) {
        i = j;
        count++;
    }
}

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

A>

B<=

C<

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<=' causes out-of-bounds access.

Using '>' or '>=' causes the loop to never run.

The loop should run while j is less than n to avoid going out of array bounds.

4fill in blank

hard

Fill both blanks to complete the function header and return statement for counting selected activities.

DSA C

int activitySelection(int [1][], int [2][], int n) {
    int count = 1;
    int i = 0;
    for (int j = 1; j < n; j++) {
        if ([1][j] >= [2][i]) {
            i = j;
            count++;
        }
    }
    return count;
}

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

Astart

Bfinish

Cactivities

Dtimes

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping start and finish arrays.

Using incorrect parameter names.

The function takes start and finish arrays as parameters to select activities.

5fill in blank

hard

Fill all three blanks to complete the main function that calls activitySelection and prints the result.

DSA C

#include <stdio.h>

int activitySelection(int [1][], int [2][], int n);

int main() {
    int start[] = {1, 3, 0, 5, 8, 5};
    int finish[] = {2, 4, 6, 7, 9, 9};
    int n = sizeof(start)/sizeof(start[0]);

    int result = activitySelection(start, finish, [3]);
    printf("Number of activities selected: %d\n", result);
    return 0;
}

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

Astart

Bfinish

Cn

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Passing arrays in wrong order.

Passing wrong variable for number of activities.

The main function passes start and finish arrays and the number of activities 'n' to the activitySelection function.