Python #

def for_loop(n: int) -> int:
    """for 循环"""
    res = 0
    # 循环求和 1, 2, ..., n-1, n
    # python for range 为左闭右开
    for i in range(1, n + 1):
        res += i
    return res

if __name == '__main__':
    print(for_loop(100))