codeforces 385 c
Description
Recently, the bear started studying data structures and faced the following problem.
You are given a sequence of integers x1, x2, ..., xn of length n and m queries, each of them is characterized by two integers li, ri. Let's introduce f(p) to represent the number of such indexes k, that xk is divisible by p. The answer to the query li, ri is the sum: , where S(li, ri) is a set of prime numbers from segment [li, ri] (both borders are included in the segment).
Help the bear cope with the problem.
Input
The first line contains integer n(1 ≤ n ≤ 106). The second line contains n integers x1, x2, ..., xn(2 ≤ xi ≤ 107). The numbers are not necessarily distinct.
The third line contains integer m(1 ≤ m ≤ 50000). Each of the following m lines contains a pair of space-separated integers, li andri(2 ≤ li ≤ ri ≤ 2·109) — the numbers that characterize the current query.
Output
Print m integers — the answers to the queries on the order the queries appear in the input.
Sample Input
6
5 5 7 10 14 15
3
2 11
3 12
4 4
9
7
0
7
2 3 5 7 11 4 8
2
8 10
2 123
0
7
Hint
Consider the first sample. Overall, the first sample has 3 queries.
- The first query l = 2, r = 11 comes. You need to count f(2) + f(3) + f(5) + f(7) + f(11) = 2 + 1 + 4 + 2 + 0 = 9.
- The second query comes l = 3, r = 12. You need to count f(3) + f(5) + f(7) + f(11) = 1 + 4 + 2 + 0 = 7.
- The third query comes l = 4, r = 4. As this interval has no prime numbers, then the sum equals 0.
查找一个区间内的,一系列数中,包含素数的个数。基本思路是:把这一系列数字中,到最大的数字Max之前是数字包含是素数的个数统计出来,然后用统计的个数区间的右端值减掉左端值减一,sum[right]-sum[left-1].因为求解的素数是包括最左端的这一个的,所以左端值应该减掉一。
比如说 对这样一个序列:5 6 7 ,则sum[1]=0;sum[2]=1;sum[3]=1;sum[4]=1;sum[5]=1;sum[6]=3;sum[7]=4; 若le=2,ri=7;ans=sum[7]-sum[1]=4;
codeforces 385 c的更多相关文章
- Codeforces 385 C Bear and Prime Numbers
题目链接~~> 做题感悟:这题属于想法题,比赛时直接做的 D 题.可是处理坐标处理的头晕眼花的结果到最后也没AC. 解题思路: 由于查询的时候仅仅考虑素数,so~我们仅仅考虑素数就能够,这就须要 ...
- CodeForces 385 D.Bear and Floodlight 状压DP
枚举灯的所有可能状态(亮或者不亮)(1<<20)最多可能的情况有1048576种 dp[i]表示 i 状态时灯所能照射到的最远距离(i 的二进制中如果第j位为0,则表示第j个灯不亮,否则就 ...
- Codeforces 385 D Bear and Floodlight
主题链接~~> 做题情绪:时候最后有点蛋疼了,处理点的坐标处理晕了.so~比赛完清醒了一下就AC了. 解题思路: 状态压缩DP ,仅仅有 20 个点.假设安排灯的时候仅仅有顺序不同的问题.全然能 ...
- Codeforces Round #385 (Div. 2) B - Hongcow Solves A Puzzle 暴力
B - Hongcow Solves A Puzzle 题目连接: http://codeforces.com/contest/745/problem/B Description Hongcow li ...
- Codeforces Round #385 (Div. 2) A. Hongcow Learns the Cyclic Shift 水题
A. Hongcow Learns the Cyclic Shift 题目连接: http://codeforces.com/contest/745/problem/A Description Hon ...
- Codeforces Round #385 (Div. 1) C. Hongcow Buys a Deck of Cards
地址:http://codeforces.com/problemset/problem/744/C 题目: C. Hongcow Buys a Deck of Cards time limit per ...
- Codeforces Round #385 (Div. 2) Hongcow Builds A Nation —— 图论计数
题目链接:http://codeforces.com/contest/745/problem/C C. Hongcow Builds A Nation time limit per test 2 se ...
- Codeforces Round #385 (Div. 2) C - Hongcow Builds A Nation
题目链接:http://codeforces.com/contest/745/problem/C 题意:给出n个点m条边,还有k个不能连通的点,问最多能添加几条边. 要知道如果有n个点最多的边是n*( ...
- Codeforces Round #385(div 2)
A =w= B QwQ C 题意:n个点m条边的无向图,其中有k个特殊点,你在这张图上尽可能多的连边,要求k个特殊点两两不连通,问最多能连多少边 分析:并查集 对原图做一次并查集,找出特殊点所在集合中 ...
随机推荐
- 白手起家搭建django app
$django-admin.py startproject web2 $cd web2/ $python manage.py startapp blog $vim web2/settings.py 注 ...
- nginx reload
iwangzheng.com Usage: nginx [-?hvVt] [-s signal] [-c filename] [-p prefix] [-g directives] Options:- ...
- 百度图片爬虫-python版
self.browser=imitate_browser.BrowserBase() self.chance=0 self.chanc ...
- 2015安徽省赛 C.LU的困惑
题目描述 Master LU 非常喜欢数学,现在有个问题:在二维空间上一共有n个点,LU每连接两个点,就会确定一条直线,对应有一个斜率.现在LU把平面内所有点中任意两点连线,得到的斜率放入一个集合中( ...
- javascript对象转化为基本数据类型规则
原文:Object-to-Primitive Conversions in JavaScript 对象转化为基础数据类型,其实最终都是用调用对象自带的valueOf和toString两个方法之一并获得 ...
- CentOS 初始化时的分区
/ ext3 8189 固定大小 空 swap 509 固定大小 /boot ext3 100 固定大小 /home ...
- python - easy_install的安装和使用
为什么要装easy_install?正常情况下,我们要给Python安装第三方的扩展包,我们必须下载压缩包,解压缩到一个目录,然后命令行或者终端打开这个目录,然后执行python setup.py i ...
- 20.python笔记之装饰器
装饰器 装饰器是函数,只不过该函数可以具有特殊的含义,装饰器用来装饰函数或类,使用装饰器可以在函数执行前和执行后添加相应操作. 装饰器是一个很著名的设计模式,经常被用于有切面需求的场景,较为经典的有插 ...
- GLSL的qualifier
uniform:从应用程序到vertex shader 到fragment shader都能使用,但是值一直不变: varying:从vertex shader到fragment shader,在fr ...
- 关于Struts2上传文件的最大Size的设置
今天使用Struts2的文件上传控件时,在struts.xml中,将处理上传的action中的fileUpload拦截器的maximumSize参数设置为5000000,上传了一个3M的文件后发现控制 ...