Fractional Knapsack Problem in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the structure for an item with weight and value.

DSA C

typedef struct {
    int value;
    int [1];
} Item;

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Aweight

Bsize

Ccost

Damount

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'size' or 'cost' instead of 'weight'.

The structure must have a field named 'weight' to store the item's weight.

2fill in blank

medium

Complete the code to calculate the value per weight ratio for an item.

DSA C

double ratio = (double)items[i].value / items[i].[1];

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Acost

Bweight

Csize

Damount

Attempts:

3 left

💡 Hint

Common Mistakes

Dividing by 'cost' or 'size' which are not defined.

The ratio is value divided by weight, so 'weight' is the correct field.

3fill in blank

hard

Fix the error in the comparison function used for sorting items by ratio.

DSA C

int cmp(const void *a, const void *b) {
    Item *itemA = (Item *)a;
    Item *itemB = (Item *)b;
    double rA = (double)itemA->value / itemA->weight;
    double rB = (double)itemB->value / itemB->weight;
    if (rA < rB) return [1];
    else if (rA > rB) return -1;
    else return 0;
}

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A1

B-1

C2

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Returning -1 instead of 1 causes ascending order.

For sorting in descending order, return 1 when rA < rB so itemB comes first.

4fill in blank

hard

Fill both blanks to update the total value and remaining capacity when taking a fraction of an item.

DSA C

if (items[i].weight <= capacity) {
    totalValue += items[i].value;
    capacity -= items[i].weight;
} else {
    double fraction = (double)capacity / items[i].weight;
    totalValue += items[i].value [1] fraction;
    capacity[2]=capacity;
    break;
}

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A*

B+

C-

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Adding fraction instead of multiplying, or subtracting capacity incorrectly.

Multiply value by fraction to add partial value, then reduce capacity to zero.

5fill in blank

hard

Fill all three blanks to complete the main loop that processes items for the fractional knapsack.

DSA C

for (int i = 0; i < n; i++) {
    if (items[i].weight <= [1]) {
        totalValue += items[i].value;
        [2] -= items[i].weight;
    } else {
        double fraction = (double)[3] / items[i].weight;
        totalValue += items[i].value * fraction;
        break;
    }
}

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Acapacity

BtotalValue

Cweight

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variables like 'totalValue' or 'weight' in place of capacity.

Use 'capacity' to check and update remaining space and calculate fraction.