Adjacency Matrix Representation in DSA Typescript - Build from Scratch

Adjacency Matrix Representation

📖 Scenario: You are working on a simple social network app. Each person can be friends with others. We want to represent these friendships using a grid where rows and columns show people, and a 1 means they are friends, 0 means not friends.

🎯 Goal: Build an adjacency matrix to show friendships between 4 people named Alice, Bob, Charlie, and Diana. Then, print the matrix to see the friendship connections clearly.

📋 What You'll Learn

Create a 4x4 adjacency matrix with exact values for friendships

Use a variable to store the number of people

Fill the matrix with 1s and 0s to represent friendships

Print the adjacency matrix row by row

💡 Why This Matters

🌍 Real World

Adjacency matrices are used in social networks, maps, and computer networks to show connections between nodes clearly.

💼 Career

Understanding adjacency matrices helps in roles like software development, data analysis, and network engineering where relationships between entities must be managed.

1

Create the adjacency matrix

Create a variable called adjacencyMatrix as a 2D array of numbers with these exact rows: [0, 1, 0, 1], [1, 0, 1, 0], [0, 1, 0, 1], [1, 0, 1, 0].

DSA Typescript

# Your code here

Hint

Use const adjacencyMatrix: number[][] = [...] to create the 2D array with the exact rows.

2

Add the number of people variable

Create a variable called numPeople and set it to 4 to represent the number of people in the network.

DSA Typescript

const adjacencyMatrix: number[][] = [
  [0, 1, 0, 1],
  [1, 0, 1, 0],
  [0, 1, 0, 1],
  [1, 0, 1, 0]
];
# Your code here

Hint

Use const numPeople: number = 4; to store the number of people.

3

Loop through the matrix to print each row

Use a for loop with variable i from 0 to numPeople - 1 to go through each row of adjacencyMatrix. Inside the loop, create a variable rowString that joins the numbers in adjacencyMatrix[i] with spaces.

DSA Typescript

const adjacencyMatrix: number[][] = [
  [0, 1, 0, 1],
  [1, 0, 1, 0],
  [0, 1, 0, 1],
  [1, 0, 1, 0]
];

const numPeople: number = 4;

# Your code here

Hint

Use for (let i = 0; i < numPeople; i++) and inside it, const rowString = adjacencyMatrix[i].join(' ').

4

Print the adjacency matrix rows

Inside the for loop, add a console.log(rowString) statement to print each row of the adjacency matrix.

DSA Typescript

const adjacencyMatrix: number[][] = [
  [0, 1, 0, 1],
  [1, 0, 1, 0],
  [0, 1, 0, 1],
  [1, 0, 1, 0]
];

const numPeople: number = 4;

for (let i = 0; i < numPeople; i++) {
  const rowString = adjacencyMatrix[i].join(' ');
  # Your code here
}

Hint

Use console.log(rowString) inside the loop to print each row.