#0211

Generate Pascal Triangle

MediumPython25 min20 XP

Problem

Return the first n rows of Pascal triangle as a list of rows. Each row should be a list of integers.

Why This Matters

Pascal triangle is a classic pattern question because it tests indexing, nested lists, and reuse of previous results.

Function Signature

def pascal_triangle(n):

Examples

Example 1

Inputn = 5

Output[[1], [1, 1], [1, 2, 1], [1, 3, 3, 1], [1, 4, 6, 4, 1]]

Every middle value is the sum of the two values above it.

Constraints

Return the exact requested value.
Handle small edge cases cleanly.
Prefer readable Python over clever shortcuts.

CodePython

def pascal_triangle(n):
    """
    Input example: n = 5
    Return: [[1], [1, 1], [1, 2, 1], [1, 3, 3, 1], [1, 4, 6, 4, 1]]
    For pattern problems, return a list of rows. Do not print the rows.
    """
    # write your code here
    return []

def pascal_triangle(n):
    """
    Input example: n = 5
    Return: [[1], [1, 1], [1, 2, 1], [1, 3, 3, 1], [1, 4, 6, 4, 1]]
    For pattern problems, return a list of rows. Do not print the rows.
    """
    # write your code here
    return []

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Core example

Inputn = 5

Expected[[1], [1, 1], [1, 2, 1], [1, 3, 3, 1], [1, 4, 6, 4, 1]]

Every middle value is the sum of the two values above it.

Hidden Test Categories

n = 0n = 1n = 8