Lesson guide
What this Python exercise practices
Build Multiplication Table is a intermediate practice lesson that focuses on loops, iteration, counters. It is designed to be solved in about 17 minutes with examples, starter code, and test feedback.
Prerequisites
- Python variables
- Lists or strings
- Basic for loop syntax
Difficulty and time
- Level
- Intermediate
- Estimated time
- 17 minutes
Practice path
Summary
Generate a rows x cols multiplication table (1-based indices) as a list of lists.
Problem statement
Write build_multiplication_table(rows, cols) that returns a list of rows lists, each containing cols integers. The value at row i and column j should be (i+1) * (j+1), using 1-based multiplication factors. If rows or cols are zero, return an empty list.
Task
Practice nested loops and building 2D lists row by row.
Examples
3x3 table
Input
build_multiplication_table(3, 3)
Output
[[1, 2, 3], [2, 4, 6], [3, 6, 9]]
Explanation
Rows and columns are 1-based. Row 2 column 3 = 2 * 3 = 6.
Input format
Two integers: rows and cols (each >= 0).
Output format
A list of lists representing the multiplication table.
Constraints
rows and cols are non-negative integers. Aim for O(rows * cols) time and space.
Samples
Sample input 0
build_multiplication_table(1, 4)
Sample output 0
[[1, 2, 3, 4]]
Explanation 0
Single row with columns 1..4.
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