Pattern printing using for loop

Aim

Program to construct patterns of stars (*), using a nested for loop.

Algorithm

1. Start
2. Take input from the user for the number of rows
3. Iterate through the range of rows
   • For each row, iterate through the range of columns
     • Print a star ('*') for each column
   • Print a newline character to move to the next row
4. End

Program

# Take input from the user
rows = int(input("Enter the number of rows: \n"))
 
# Iterate through the range of rows
for i in range(rows):
    # Iterate through the range of columns
    for j in range(i+1):
        # Print a star for each column
        print("*", end="")
    # Move to the next row
    print()

Sample Input/Output

Enter the number of rows:
5
*
**
***
****
*****

Explanation

• The program takes the number of rows as input from the user.
• It then uses a nested for loop to iterate through the rows and columns to print the pattern of stars.
• In each row, the number of stars printed increases by 1, creating a triangular pattern.

Complexity Analysis

The time complexity of this program is O(n^2), where n is the number of rows. This is because the program uses a nested loop to print the pattern, resulting in n^2 iterations.

The space complexity of the program is O(1) as the program uses a fixed amount of space to store variables and does not depend on the input size.

How can you improve this program?

1. You can modify the program to print different patterns of stars by changing the logic inside the nested loop.
2. You can add more user-friendly features, such as allowing the user to choose the character to print instead of just a star.

Summary

This program demonstrates how to construct patterns of stars using a nested for loop in Python. It is a simple example of using loops to create visual patterns.