Introduction
Matrix Traversal means visiting every element of a 2D matrix systematically.
The task is to:
- traverse rows
- traverse columns
- access every matrix element
Example:
Input Matrix:1 2 3
4 5 6
7 8 9
Output:
1 2 3 4 5 6 7 8 9
Explanation:
Traversal starts from first row.Elements are visited one by one.This problem is one of the most important applications of:
Nested LoopsConstraints
1 <= Rows, Columns <= 10^3Approach 1 : Row Wise Traversal
Explanations:
Explanation:
The idea is:
- traverse row by row
- visit every column inside row
Steps:
- Start from first row.
- Traverse all columns.
- Move to next row.
This is the most basic matrix traversal technique.
Dry Run
Matrix:1 2 3
4 5 6
7 8 9
Row 1:
1 2 3
Row 2:
4 5 6
Row 3:
7 8 9
Output:
1 2 3 4 5 6 7 8 9
Practice :
Complexity Analysis :
Time Complexity:- O(rows × cols)Explanation :
Every matrix element is visited once.
Space Complexity:- O(1)
Explanation :
No extra space is used.
Approach 2 : Column Wise Traversal
Explanations:
Explanation:
The idea is:
- traverse column by column
- visit every row inside column
This changes traversal order.
Dry Run
Matrix:1 2 3
4 5 6
7 8 9
Column 1:
1 4 7
Column 2:
2 5 8
Column 3:
3 6 9
Output:
1 4 7 2 5 8 3 6 9
Practice :
Complexity Analysis
Time Complexity:- O(rows × cols)Explanation :
Every matrix element is visited once.
Space Complexity:- O(1)
Explanation :
No extra space is used.
Why This Problem is Important
This problem builds the foundation for:
- 2D Arrays
- Matrix manipulation
- Nested loops
- Grid traversal
- Coordinate-based problems
Real-World Applications
Matrix traversal concepts are used in:
- Image processing
- Game development
- Spreadsheet systems
- Graph algorithms
- Grid simulations
Common Beginner Mistakes
- Incorrect row/column indexing
- Out of bounds errors
- Wrong loop conditions
- Confusing rows and columns
- Infinite loops
Interview Tip
Interviewers often expect:
- proper nested loop usage
- correct indexing
- matrix understanding
- traversal optimization
Always explain:
- row traversal logic
- column traversal logic
Related Questions
- Row & Column Sum
- Spiral Matrix
- Rotate Matrix
- Search in Matrix
- Matrix Transpose
Final Takeaway
The Matrix Traversal problem is one of the most important beginner matrix problems.
It teaches:
- matrix traversal
- nested loops
- row & column access
- grid manipulation
Understanding this problem builds a strong foundation for:
- advanced matrix problems
- graph traversal concepts
- interview-level data structure questions.