Matrix Chain Multiplication in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the matrix dimensions array.

DSA C

int arr[] = {10, 20, 30, 40, [1];

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A30

B50

C40

D60

Attempts:

3 left

💡 Hint

Common Mistakes

Using 40 instead of 50 as the last dimension.

The last dimension must be 50 to represent matrices of dimensions 10x20, 20x30, 30x40, and 40x50.

2fill in blank

medium

Complete the code to set the base case for the DP table in matrix chain multiplication.

DSA C

for (int i = 1; i < n; i++) {
    m[i][i] = [1];
}

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A0

B1

Ci

Dn

Attempts:

3 left

💡 Hint

Common Mistakes

Setting the base case to 1 or i instead of 0.

The cost of multiplying one matrix is zero because no multiplication is needed.

3fill in blank

hard

Fix the error in the loop condition to correctly iterate over chain lengths.

DSA C

for (int L = 2; L <= [1]; L++) {
    // code
}

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An-1

Bn+1

Cn

Dn-2

Attempts:

3 left

💡 Hint

Common Mistakes

Using n or n+1 causes out-of-bound errors.

The chain length L goes up to n-1 because there are n matrices and n-1 gaps between them.

4fill in blank

hard

Fill both blanks to correctly compute the minimum multiplication cost.

DSA C

for (int k = i; k < j; k++) {
    int cost = m[i][k] + m[k+1][j] + arr[i-1] [1] arr[k] [2] arr[j];
    if (cost < m[i][j])
        m[i][j] = cost;
}

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A*

B+

C-

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' or '-' instead of '*' causes wrong cost calculation.

The cost formula multiplies the dimensions: arr[i-1] * arr[k] * arr[j].

5fill in blank

hard

Fill all three blanks to complete the nested loops for matrix chain multiplication.

DSA C

for (int L = 2; L <= [1]; L++) {
    for (int i = 1; i <= n - L + [2]; i++) {
        int j = i + L - [3];
        // compute m[i][j]
    }
}

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

An-1

B1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong loop bounds causing index errors.

L goes up to n-1; i goes up to n-L+1; j is i+L-1 to cover the chain.