Spiral Matrix Traversal in DSA C - Build from Scratch

Spiral Matrix Traversal

📖 Scenario: You are working with a 2D grid of numbers, like a map of city blocks with house numbers. You want to walk around the blocks in a spiral path, starting from the top-left corner and moving inward, collecting the house numbers in the order you visit them.

🎯 Goal: Build a program that takes a fixed 3x3 matrix and prints the numbers in the order they appear when traversed in a spiral pattern.

📋 What You'll Learn

Create a 3x3 integer matrix with exact values

Use variables to track the boundaries of the matrix

Implement the spiral traversal logic using loops

Print the elements in spiral order separated by spaces

💡 Why This Matters

🌍 Real World

Spiral traversal is useful in image processing, games, and UI layouts where you need to process elements in a circular inward pattern.

💼 Career

Understanding matrix traversal techniques is important for software engineers working with grids, graphics, and algorithm optimization.

1

Create the 3x3 matrix

Create a 3x3 integer matrix called matrix with these exact values: 1, 2, 3 in the first row, 4, 5, 6 in the second row, and 7, 8, 9 in the third row.

DSA C

# Your code here

Hint

Use a 2D array with three rows and three columns. Each row is enclosed in braces and separated by commas.

2

Set up boundary variables

Add four integer variables called top, bottom, left, and right. Initialize top to 0, bottom to 2, left to 0, and right to 2.

DSA C

int matrix[3][3] = {
    {1, 2, 3},
    {4, 5, 6},
    {7, 8, 9}
};
// Your code here

Hint

These variables will help you keep track of the current edges of the matrix as you spiral inward.

3

Implement spiral traversal logic

Write a while loop that continues as long as top <= bottom and left <= right. Inside the loop, use for loops to traverse from left to right on the top row, then increment top. Next, traverse from top to bottom on the right column, then decrement right. Then traverse from right to left on the bottom row, then decrement bottom. Finally, traverse from bottom to top on the left column, then increment left. For each element visited, print it followed by a space.

DSA C

int matrix[3][3] = {
    {1, 2, 3},
    {4, 5, 6},
    {7, 8, 9}
};

int top = 0;
int bottom = 2;
int left = 0;
int right = 2;

// Your code here

Hint

Follow the edges in order: top row left to right, right column top to bottom, bottom row right to left, left column bottom to top. Update boundaries after each edge.

4

Print the spiral traversal result

Add a printf statement to print a newline character '\n' after the spiral traversal is complete.

DSA C

int matrix[3][3] = {
    {1, 2, 3},
    {4, 5, 6},
    {7, 8, 9}
};

int top = 0;
int bottom = 2;
int left = 0;
int right = 2;

while (top = left; i--) {
            printf("%d ", matrix[bottom][i]);
        }
        bottom--;
    }

    if (left = top; i--) {
            printf("%d ", matrix[i][left]);
        }
        left++;
    }
}

// Print a newline character

Hint

After printing all elements, print a newline to move the cursor to the next line.