Python/1-100の和

end = 100

# 1~100の総和をfor文で求める
n = 0
for i in range(1, end+1):
    n += i

print(n)

# 公式を使う場合
n = (end * (end+1)) * 0.5
n = int(n)
print(n)

# sum関数を使う場合
lst = []
for i in range(1, end+1):
    lst.append(i)

n = sum(lst)

print(n)