Logic Building/Phase 3 - Level 3: Pattern Recursion/Program

Print Triangle (Bottom-Up) Recursively

Print inverted triangle recursively.

Logic BuildingIntermediate

Logic Building

def print_stars(n):
    if n == 0:
        return
    print("*", end="")
    print_stars(n - 1)

def print_triangle(n, row=1):
    # Base case
    if row > n:
        return
    
    # Recurse first
    print_triangle(n, row + 1)
    # Then print current row
    print_stars(row)
    print()

# Test
n = int(input("Enter rows: "))
print_triangle(n)

Output

Enter rows: 5
*****
****
***
**
*

Recurse first, then print (reverse order).

Key Concepts:

Recurse before printing
Prints in reverse order
Creates inverted triangle

Print Triangle (Top-Down) Recursively

Number Patterns Recursively