Logic Building/Phase 2 - Level 1: Basic Looping/Program

Print Alternating Numbers

Print numbers 1 to n with alternating signs.

Logic BuildingBeginner

Logic Building

# Take n as input
n = int(input("Enter n: "))

# Print alternating
for i in range(1, n + 1):
    if i % 2 == 0:
        print(-i, end=" ")
    else:
        print(i, end=" ")
print()

Output

Enter n: 5
1 -2 3 -4 5

Alternate signs based on even/odd.

Key Concepts:

Check if number is even
Print negative for even, positive for odd
Create alternating pattern

Sum of Squares Up to N