[Python]SW Expert - 지그재그 숫자(D2)

문제출처 - https://swexpertacademy.com/main/code/problem/problemDetail.do?contestProbId=AV5PxmBqAe8DFAUq&categoryId=AV5PxmBqAe8DFAUq&categoryType=CODE

SW Expert Academy

t = int(input())

for case in range(t):
    n = int(input())
    answer = 0

    for i in range(1, n+1):
        if i % 2 == 1:
            answer += i
        else:
            answer -= i

    print("#%d" % (case+1), answer)