题解 | #[NOIP2015]金币#
[NOIP2015]金币
http://www.nowcoder.com/practice/8f71f5670e6a45118d24d13868a2da9e
K = int(input())
coin = 0
i = 1
current = 0
# 先按每组天数刚好占满的情况算总金币
while current <= K:
current += i
coin += i*i
i += 1
# 减去超出的天数的金币
coin -= (current-K)*(i-1)
print(coin)
查看17道真题和解析
