题意翻译 给你一串数列a.对于一个质数p,定义函数f(p)=a数列中能被p整除的数的个数.给出m组询问l,r,询问[l,r]区间内所有素数p的f(p)之和. 题目描述 Recently, the bear started studying data structures and faced the following problem. You are given a sequence of integers x1,x2,...,xn x_{1},x_{2},...,x_{n} x1,x2,.…
385C - Bear and Prime Numbers 思路:记录数组中1-1e7中每个数出现的次数,然后用素数筛看哪些能被素数整除,并加到记录该素数的数组中,然后1-1e7求一遍前缀和. 代码: #include<bits/stdc++.h> using namespace std; #define ll long long #define pb push_back #define mem(a,b) memset((a),(b),sizeof(a)) const int INF=0x3f…
Codeforces 385C Bear and Prime Numbers 其实不是多值得记录的一道题,通过快速打素数表,再做前缀和的预处理,使查询的复杂度变为O(1). 但是,我在统计数组中元素出现个数时使用了map,以至于后面做前缀和的累加时,每次都要对map进行查询,以至于TLE.而自己一直没有发现,以为是欧拉筛对于这道题还不够优,于是上网搜题解,发现别人的做法几乎一样,但是却能跑过,挣扎了许久才想起是map的原因.map的内部实现是一颗红黑树,每次查询的复杂度为O(logN),在本来时…
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 represe…
第一眼看这道题目的时候觉得可能会很难也看不太懂,但是看了给出的Hint之后思路就十分清晰了 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…
C. Bear and Prime 100 time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output This is an interactive problem. In the output section below you will see the information about flushing the output. Bea…
C. Bear and Prime 100 time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output This is an interactive problem. In the output section below you will see the information about flushing the output. Bea…
Sum of Consecutive Prime Numbers Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 20050 Accepted: 10989 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representatio…
题目链接: 传送门 Sum of Consecutive Prime Numbers Time Limit: 1000MS Memory Limit: 65536K Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representations does a given positive intege…
C. Bear and Prime 100 time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output This is an interactive problem. In the output section below you will see the information about flushing the output. Bea…
Sieve of Eratosthenes (素数筛选算法) Given a number n, print all primes smaller than or equal to n. It is also given that n is a small number. For example, if n is 10, the output should be “2, 3, 5, 7″. If n is 20, the output should be “2, 3, 5, 7, 11, 13,…
题目链接: C. Bear and Prime 100 time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output This is an interactive problem. In the output section below you will see the information about flushing the outpu…
Problem Description Give you a lot of positive integers, just to find out how many prime numbers there are. Input There are a lot of cases. In each case, there is an integer N representing the number of integers to find. Each integer won't exceed 32-…
Alexandra and Prime Numbers Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1658 Accepted Submission(s): 565 Problem Description Alexandra has a little brother. He is new to programming. One…
How many prime numbers Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 14684 Accepted Submission(s): 5091 Problem Description Give you a lot of positive integers, just to find out how many…
Problem Description Give you a lot of positive integers, just to find out how many prime numbers there are. Input There are a lot of cases. In each case, there is an integer N representing the number of integers to find. Each integer won’t exce…
题目链接 Description Final Pan likes prime numbers very much. One day, he want to find the super prime numbers.A prime numbers $n$($n$>4) is a super prime number only if $n$-4 and $n$+4 are both prime numbers,too. Your task is really easy:Give $N$,find t…
Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representations does a given positive integer have? For example, the integer 53 has two representations 5 + 7 + 11 + 13 + 17 and 5…
Bear and Prime 100Crawling in process... Crawling failed Time Limit:1000MS Memory Limit:262144KB 64bit IO Format:%I64d & %I64u Submit Status Practice CodeForces 680C uDebug Description Input Output Sample Input Sample Output Hint …
Website:http://srinvis.blogspot.ca/2006/07/hash-table-lengths-and-prime-numbers.html This has been bugging me for some time now... The first thing you do when inserting/retreiving from hash table is to calculate the hashCode for the given key and the…
Sum of Consecutive Prime Numbers Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 25225 Accepted: 13757 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representatio…
UVA 10539 - Almost Prime Numbers 题目链接 题意:给定一个区间,求这个区间中的Almost prime number,Almost prime number的定义为:仅仅能整除一个素数. 思路:既然是仅仅能整除一个素数,那么这些数肯定为素数的x次方(x > 1),那么仅仅要先打出素数表,然后在素数表上暴力找一遍就能够了,由于素数表仅仅要找到sqrt(Max),大概100W,然后每一个数找的复杂度为log(n),这样复杂度是能够接受的. 代码: #include <…
