Adjacency Matrix Representation in DSA Typescript - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize an adjacency matrix for a graph with n vertices.

DSA Typescript

const adjacencyMatrix: number[][] = Array.from({ length: n }, () => Array(n).fill([1]));

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A0

B1

C-1

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 instead of 0 will incorrectly show edges where there are none.

Using null or -1 is not standard for adjacency matrices.

The adjacency matrix is initialized with 0s to indicate no edges between vertices initially.

2fill in blank

medium

Complete the code to add an edge from vertex u to vertex v in the adjacency matrix.

DSA Typescript

adjacencyMatrix[[1]][v] = 1;

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Av

Bu

C0

Dn

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping u and v will add the edge in the wrong direction.

Using 0 or n as index will cause errors.

To add an edge from u to v, set the matrix at row u and column v to 1.

3fill in blank

hard

Fix the error in the code that checks if there is an edge from u to v.

DSA Typescript

if (adjacencyMatrix[u][[1]] === 1) { console.log('Edge exists'); }

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Av

Bu

C0

Dn

Attempts:

3 left

💡 Hint

Common Mistakes

Using u for both indices checks a self-loop incorrectly.

Using 0 or n as index causes out-of-bounds errors.

The second index should be v to check the edge from u to v.

4fill in blank

hard

Fill both blanks to create a function that returns true if there is an edge from source to target.

DSA Typescript

function hasEdge(adjacencyMatrix: number[][], source: number, target: number): boolean {
  return adjacencyMatrix[[1]][[2]] === 1;
}

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Asource

Btarget

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping source and target indices will check the wrong edge.

Using incorrect variable names causes errors.

The function checks adjacencyMatrix[source][target] to see if the edge exists.

5fill in blank

hard

Fill all three blanks to create a function that builds an adjacency matrix from a list of edges.

DSA Typescript

function buildAdjacencyMatrix(n: number, edges: [number, number][]): number[][] {
  const matrix = Array.from({ length: n }, () => Array(n).fill(0));
  for (const [[1], [2]] of edges) {
    matrix[[3]][[2]] = 1;
  }
  return matrix;
}

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

Au

Bv

Attempts:

3 left

💡 Hint

Common Mistakes

Using v as the row index and u as the column index swaps edge direction.

Not destructuring edges properly causes errors.

The function loops over edges, destructuring each edge into u and v, then sets matrix[u][v] = 1.