传送门:https://codeforces.com/contest/691/problem/F
题意:给你n个数和q次询问,每次询问问你有多少对ai,aj满足ai*aj>=q[i],注意 a*b 与 b*a是不同的
题解:sum[i]记录的是两个数乘积为i的方法数,然后前缀和记录小于等于乘积为i的方法个数,输出答案就容斥一下,因为n个数最多组成n*(n-1)/2对数,减去小于乘积为q[i]的数后即为乘积大于等于q[i]的方法个数
为什么可以暴力是因为注意到了值域的范围为3e6,调和级数的复杂度为nlogn,O(能过)
代码:
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